Pinball Medic's Additional Coin-Op Arcade Technical, Maintenance Tips and Techniques

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Ask Our Coin-Op Arcade and Pinball Game Tech (Aby Normal) a Technical Question.Tech Question Submission.
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information on supporting our Tech Tip pages.

21. Can I leave a game powered on all of the time?

22. Do all pinball games use the same size of game ball or are there pinball specific game balls?

23. Are there differences between pinball game balls from different suppliers and what can this difference do to a playfield?

24. I'm confused about fuses. How is a fuse rated and what fuse types are in Coin-Op Arcade games?

25. What types and sizes of cabinets are there and does the cabinet type add to a game's worth?

26. What are the sizes of dot matrix displays (DMD) and are there any differences between display manufacturers?

27. Flipper Bushing types de-mystified and flipper scrape damage caused by worn out bushings explained.

28. New reproduction versus old original backglass/scoreboard glass.

29. Line voltage and the dangers of High Tapping an arcade.

30. What methods can be used to fix weak or non-operating flippers?

31. Types and photos of pinball playfield lockdown bars.

32. Why can't Coin-Op repair shops fix home version pinball games?

33. Why would someone wax a playfield and what wax would they use?

34. What kind of oil can be used on arcade game motors and pinball leg level adjusters?

21. Can an arcade game be left powered on all of the time?
Updated 9-20-19
At Commercial arcade sites, game room operators / owners will keep a game powered on twenty four hours a day, seven days a week, to maximize a game's profit potential during the typical three year life span of a game. After this time, the game usually does not pull in enough quarters/players, has paid for itself and made some profit for the Arcade. It is now considered obsolete and will be sold off or parted out..
Arcade game manufacturers design a game to be powered on all of the time because they will be during their three year life spans in the arcade. Unlike disposable consumer products, a full sized arcade is built to last for years powered on all of the time.

PROs for keeping a game powered on:
It's like playing Russian Roulette when first powering on a game. You never know when something random inside of the game will be destroyed by power supply spikes, thermal shocks and old warn out electronic parts like capacitors.

-- Light bulbs tend to burn out when the power is first applied to them because they have a cold filament with a low resistance. A glowing hot filament has a high resistance and therefore limits the current drawn through it. The inrush of current flowing into a weakened over time cold filament can cause it to break and destroy the bulb.

-- Large electrolytic capacitors are briefly like shorted loads to a power supply when they have no charge in them
(See Tech Question 16 for more info on large capacitors).
When the game is first powered on, the power supply will appear to have been shorted out for a few milliseconds (capacitor's charging time) causing a high current flow and possibly a voltage spike. The surge of current can destroy bridge rectifiers, power transformers, game logic and the power supply input/output connectors.
If arcade games used good capacitors and power supply design then the first powered-on surge would never occur or for a very short time and only when the game is powered on after being off for a long period of time (discharged capacitors).
All current/voltage power-on surges should be limited by the power supply (a "soft start" power supply).
No one has ever said a classic arcade or pinball game's power supply has ever been correctly designed.
The power-on surge can be a major source of power supply and game electronics destruction.

-- In modern arcade games with adequate game cabinet ventilation, constant game temperature inside of the game is maintained. Electronics don't like to work properly at either too cold or too high of a temperature. When they are cold and asked to suddenly start to function, they can be destroyed by what is known as thermal shock (Thermal shock - raising the temperature of an electronic component too fast). Game parts including electronics and batteries will last longer if the internal cabinet temperature is keep constant.

-- Light bulbs in playfield inserts that blink (or are in electronic pinballs) don't burn for long and don't build up heat, however, the always on EM pinball insert bulbs can cause damage to playfield inserts. Plastics on newer games (1990-) are not as susceptible to warping from the heat produced by the General Illumination lamps.

See Tech Question 9 Monitor Cap Kits for capacitor replacement info.

Leaving a game running all of the time will eventually cause destruction to expensive game parts (monitors, power supplies and displays).
We believe a home use only (H.U.O.) game should be left on as long as it is being played.
The destruction of game parts over a long period of game operation out ways the possible parts repair or replacement costs caused by powering up a game to play it. Leaving the game powered off also saves on the electric bill.
A coin operated game in an Arcade will need to be powered-up at all times to get people to play them.

CONs for keeping a game powered on:
EM Pinball:
Heat generated by the general illumination lamps (G.I.) can warp playfield plastics and cause the ink on scoreboard glasses to flake.
Electromechanical pinball machines usually are the most sensitive to plastic warping and ink flaking because most of them are all 30+ years old.
Plastic durability and resistance to heat has improved over the years making newer electronic game plastics less acceptable to heat.
See Tech Question 1 regarding bulb type replacement to help prevent plastic and scoreboard ink destruction.

-- 'Game on' or 'Lock' relays, score/playfield motors, coin-lockout coils and any other part of an electromechanical pinball that stays energized all the time will eventually heat up over the years and burn themselves out. The heat they produce also adds to the overall build up of heat inside the game.

Light bulbs don't last forever and have to be replaced eventually and applying power to a cold bulb filament can cause the bulb's filament to burn out due to inrush currents caused by a low Ohmage cold filament
On Williams and other pinball games, the flasher bulbs are either kept slightly lit ('keep alive' circuits) or 18 volts are applied during the flashing of the bulb (on a 12 volt bulb) to help solve the current inrush problem.

Electronic Pinball
Solid State electronic pinball games use neon score display tubes, Dot Matrix Displays (DMD) or LED displays. Both display tubes and DMD displays eventually out-gas ( See Gottlieb display rejuvenation ) or can burn out their non replaceable driver chips due to age and length of use.

-- Display driver electronics can be destroyed by electrical spikes and other disasters (old display tubes). Displays are one of the most expensive and labor intensive parts to replace on a pinball game and have a limited life span.

-- Electronics in Power Supplies, CPU / Logic chips and even monitors all produce heat. This heat can build up inside of a game and decrease electronic part life spans. Large electrolytic capacitors are made to withstand only a limited amount of heat and can be greatly affected by heat and age.

-- Incandescent light bulbs don't last forever and produce more heat then light. General Illumination bulbs (G. I. lamps) are on during the entire time the game is powered up. Over extended periods of time (years), the heat built up by G. I. bulbs can warp playfield plastics, marquees, coin slot pricing cards and other game specific parts.
See Tech Question 1 for more information on bulb types.

Note: We recommend changing out all the #44 light bulbs with #47 ones to reduce the total current draw and heat build up of the game. This bulb swap out also helps prevent the G. I. wire connectors from burning because of excessive current draw.
Video games always powered on problems:
Electronics in Power Supplies, CPU/Logic chips and even the CRT in monitors all produce heat. This heat can build up inside of a game and decrease these same electronic component's life spans. Cabinet fans are often found non working due to excessive dirt packed into their screens or are frozen because of age. This can over heat an arcade and cause capacitors and electronics to go bad prematurely.

-- Large electrolytic capacitors are made to withstand only a limited amount of heat and can be greatly affected by it.

-- Modern video games include fans that dissipate excess game generated heat and use switching mode power supplies that don't produce as much heat as the analog power supplies. Older classic games do not have fans or more efficient power supplies and can build up this destructive heat.

-- A poorly designed and programmed video game will leave an image perpetuity on a section of the screen.
Examples of this are score totals, game title, top ten players list and game demos that don't refresh the screen very often. Images will eventually burn themselves into the picture tube and will permanently darken a region of the screen. This kind of burn-in can't be repaired. Leaving a video game powered on all of the time speeds the monitor image burn-in process.
See Tech Question 5 for more info on monitor screen image burn-in.
Tech Note: Also caused by bad game design is magnetized monitors. Speakers that are mounted too close to the CRT can magnetize metal parts inside the monitor's picture tube and cause all sorts of destroyed video images. Luckily, a demagnetizer ring can be used to rid the screens of this distraction, in most cases.
22. Are all pinball game balls the same size?

The standard diameter pinball game ball is 1 1/16 of an inch.
Game balls come in a verity of sizes from 1/8 inch all the way up to the Billiards table Que ball used in the Hercules pinball (the largest pinball game manufactured in the USA).

The ball's price varies little between the smaller and standard size game ball. This was never an issue with the game's manufacturer.
Pinball Medic only sells the standard sized, 80 gram pinball game ball

Usually, the game ball size only various by a very small amount when a non-standard sized ball is required. For example; a one inch ball is used instead of a normal ball (one and one sixteenth of an inch sized ball). This is done to increase the speed of the ball.
See Question 44 to realize what a non-informed refurbish or route person can cause with the wrong sized ball.

NOTE: We often find the standard size and finish game ball inside a game designed for a different sized and grade ball. The game operator either didn't know or didn't what to spend anything but the bare minimum to get the game operational.
Twilight Zone's "Power Ball" - This pinball uses standard sized metal game balls and one 20% lighter then steel, Ivory-colored 1-1/16" diameter, 65 gram ceramic ball. This ball does not react to magni-coils under the playfield but does provide a faster moving game ball.

Nerdy Note: A larger ball has the effect of weakening flipper and pop bumper strength because of simple physics. It has a higher mass and is therefor harder to start to move or stop it from moving. Flippers will have a hard time flipping a large ball all the way to the top of the playfield. Pop Bumpers could have an easier time of making playfield artwork destruction because the increased angle of interaction between a large diameter ball and the ring and rod assembly.

The majority of pinball games use the standard sized game ball. However, some use a smaller diameter game ball. These smaller game balls have less mass (weight) and can travel and change directions faster then a larger diameter ball. This provides for faster game play without the game's manufacturer having to pay more for stronger solenoid coils that tend to lower the games mean time before failure rate (MTBF).

Standard and non-standard sized game balls.
NOTE: Ball's diameter is measured in inches.
1 1/16
Inch ball is used on the majority of both EM and SS Pinball games from most game manufacturers. This is the standard sized ball.
1 Inch Ball - Used on only a few electromechanical pinball machines from the 1960's and on Bally's TRUCKSTOP to improve ramp shot playability.
1 1/4 Ball - This is the oversize ball used in Gottlieb's STRIKES & SPARES (14 balls required for this game) bowling theme pinball table.
Part Number = Gottlieb Part Number 31134
15/16 Ball - Used on the Roll Tilt assembly in many Bally and Stern pinball machines.
Equivalent to: Bally Part M-168-50, Midway Part 0017-00009-0547, Williams 20-6519, Williams Part 20A-6519
3/4 Ball is used in many pinball and pitch & bat machines:
Williams games: SLUGFEST, LINE DRIVE, UPPER DECK, PENNANT FEVER, HYPERBALL (55 balls used) and used on roulette wheels.
Gottlieb MONTE CARLO, Bally SPEAKEASY, Williams MILLIONAIRE (Reference Williams part #20-6520)

Read Question 23 to know how a ball is made.
See Question 44 on ball size verses gameplay speed.
22a. is now question number 44. Can a game be equipped with a smaller/larger game ball to multiply or decrease the game's playing speed?
23. Are there differences between pinball game balls from different suppliers and what can this difference do to a playfield?
Pinball Medic's Laser Brand pinball game balls Game balls come in a verity of degrees of finishes and hardness.

Standard non-polished - This is the cheapest grade of game ball. Its hardness can very widely between suppliers. It has not been polished to any great extent and can look dull when compared to even the least polished game ball.

Highly polished ball - A game ball can not be tumble polished. The number of ball to ball hits would dull and flatten the normal surface hardened (1000 grade) game ball if tumble polishing were used.
A vibration polisher is used to polish the game ball's surface. Polishing in no way makes the ball's surface harder. It just makes it shiny. Highly polished balls hardness can very widely between suppliers.

Mirror finished ball - This implies the game ball has been polished for at least 24 hours. These are the clearest mirror like finish balls available on the market.

Coated or Glazed - This usually indicates a mirror finish game ball that has been coated with a super hard clear finish much like the 'Diamond Coated' or'Hard Coated' playfields found in most modern electronic pinball games or clear coat used over modern car paints. The coating helps preserve the ball's finish. This level of ball finish has the highest retail cost. This can be $8 or higher a ball.
If you wanted to replace the game balls in an Apollo 13 pinball game with this type of ball you would spend over $104 plus shipping for just the game balls. The Apollo 13 pinball has a 13 ball multi-ball mode.

Gold and Stainless - Gold colored/coated balls are used in very few games. These can be very expensive and can be as low grade as a non-polished ball. Usually, this type of ball isn't glazed. The cheap ones have inferior gold coatings and can rust and pit very easily.
Stainless steel game balls will never rust inside of a game, however, they can't be polished to as high of a degree as a mirrored finish ball. It's also very hard to find a ball supplier for this kind of ball and they are not as hard as a grade 500 laser game ball Some grades of stainless are not very influenced by magnetic fields and sometimes don't interact well with Magni-Saves and other magnetic ball capture devices.

NOTE: Some refurbishment / repair shops will replace the game ball with the cheapest standard non-polished ball they can find. They don't even bother to change a rusty ball and even leave this bad ball in the game while shipping it.

Pinball Medic believes it is far more important to have a clean playfield using a good quality game ball that will have to be replaced in a six to twelve month time frame (on a light home use game), then it is to buy an exotic / expensive game ball and leave it in the game for years.
Even a stainless steel ball will develop dents and surface scratches. Every game played with a bad ball decreases the game's value and playability.

Game balls are a very intense subject for some game collectors. They can also be one of the major sources of playfield wear. Game balls are one of the cheapest enhancements to playfield performance, game cosmetics and are the number one neglected part of a pinball, next to rubber rings

Most modern games have more then one ball. Multi ball collisions can cause ball flat spots and dents. An out of round or rusty game ball will cause the ball to roll unpredictably and damage the playfield's artwork. Game balls, unless you go for glazed or stainless are so cheap that we can't help but install them in every game we refurbish and most of the games we repair. Why decrease a game's looks and durability for a $2 ball?

The ball's hardness is at least as important as its finish. Usually ball suppliers will never tell any customer the hardness and roundness specs for the ball they sell. These specs can very wildly between ball manufactures.

The most important finish property is how long it will stay on the ball and gold balls aren't known for this. Game ball color finishes like gold are somewhat cosmetic. A typical pinball player will not notice he is playing a game made to have a gold colored ball installed. Only experienced game collectors usually would know.

Glazed or Stainless balls have a lot longer life spans for a lot more money. Even these types of balls can get dented and destroy the playfield artwork.

Specialty Balls - There are a few game balls that don't fit a major ball size or quality category.
Twilight Zone pinball's "Power Ball" is one such case. This game uses standard sized metal game balls and one 20% lighter then steel, Ivory-colored 1-1/16" diameter, 65 gram ceramic ball. This produces a much faster and non magnetically influenced game ball. This one special ceramic ball can cost more the $40.

Newton balls are another example.
A Newton ball is created by taking a perfectly good game ball and welding a threaded stud to the ball's surface. The ball is then bolted to the playfield.
Usually, a captured ball (captured ball=a normal game ball that can only roll in a confided path) is placed behind a Newton ball. The force of the game ball hitting a Newton ball is used to roll the captured ball up the playfield to hit a target or row over switch(s).
Newton balls don't normally have any ball specs and are probably made out of the cheapest ball that could be found. This makes the welding and polishing processes easier.
Newton balls tend to rust, have a large flat spot on the side that gets hit by the game ball and can very easily destroy its mounting hole if the nut that mounts it becomes loose.
While they are more expensive to buy then normal cheap game ball, Newton balls should be replaced almost as often as the game ball. Newton balls cause a degradation of a new game ball because hitting one causes metal on metal interactions between the Newton ball and the fast moving game ball.
In general: (updated 9-20-19)
Dirty, Rusty or dented game balls cause the majority of playfield artwork destruction.

2) A hard, good quality game ball can prolong both the ball and playfield artwork's life spans.

3) Balls and rubber rings are considered consumable game parts and need to be replaced on a regularly scheduled basis to preserve the machine for the next generation of pinball players and collectors.

4) Replace Newton balls almost as often as the game ball. Make sure the mounting nut is secured or the mounting hole can get destroyed.
It is OK to use removable strength 'Loctite', a lock washer and/or a Nylon lock nut on the mounting screw.
We normally install a washer under everything to help keep the Newton ball from harming the wood playfield.

5) Always use the correct size of ball in your game.
Smaller or larger diameter balls can do damage to a game that was designed for a stock 1 1/16 inch game ball.

6) Not all steel balls are strongly attracted to electromagnets. There are forms of stainless steel or high carbon steel balls that are weakly attracted to under the playfield magnetic coils (Magna Saves electromagnetic coils).
This can cause a game ball to roll over Magna-Saves or other ball capture devices and therefore change the way the game plays. There is a Power Ball from the Twilight pinball that will not be affected by any form of coil. However, it is white in color and is easy to spot.

7) Applying a special hard wax to a playfield when you replace the game balls is another way to protect the playfield and to slightly accelerate the game play.

8) Except for some coated and all stainless steel balls, game balls will rust eventually just sitting inside of the game. Remember to replace often. A rusty game ball is just about the worst punishment for a playfield, besides letting water get on it.
24. How are fuses rated?

Caution: It is both a danger and a fire hazard to over fuse a circuit or put foil around a blown fuse. It is equally hazardous to over load a wall plug and its circuit breaker. Loads should only draw 80% of the rated current capacity of the circuit breaker. If a house circuit breaker is rated for 20 Amps then only 16 Amps should ever be drawn at any one time. This includes other wall sockets and appliances collected to the same circuit breaker.

See Tech question number 13 on our Tech Page for more information about circuit breakers and multiple plug adaptors. Also, see our Coin-Op
Catastrophe Collection page for photos of bad fusing practices.

Fuse Voltage Rating: Fuses are rated in both current and in volts that can be safely disconnected by the fuse. Older automobiles take a fuse that looks just like a fuse in a coin-op game and can even be inserted in a regular fuse holder. Automobile fuses are rated for 32 volts. If they are installed in a 50 volt flipper circuit the fuse might not open up enough to totally disconnect the circuit from the power source in the case the fuse's current rating is exceeded. This can cause arcing inside of the fuse and heat it up to a point that it desolders itself from the circuit board. This condition can also allow the circuit the fuse was supposed to protect to over heat and burn itself out. Don't risk an expensive and perhaps non-replaceable electronic game part on a 30 cent fuse. Always replace fuses with one rated for at least 125 volts.

Important Note: The higher the voltage a fuse is rated the better the fuse.
If you don't know the voltage a circuit uses then replace the blown fuse with a 250 volt rated fuse. There shouldn't be any fuse protected circuit inside an arcade game (not even inside a monitor) that is supplied with greater then 250 volts (The highest fuse protected voltage circuit is the pinball game's display tube power supply at 190 volts).

20 mm fuses used in WPC - 95 Pinball machinesFuses come in many sizes and have different end connectors.
The majority of the fuses in coin-op games are of the straight glass body type (AGC) and are 1.25 inches in length (see photo at bottom of this question). They are made with a wire inside of a glass cylinder with crimped on metal contacts on its ends.
The fuse photo to the left is of a 20 mm glass fuse used in the Williams WPC - 95 pinball board system.

Fast or Slow Blow? - A fuse's element can indicate a fast or slow blow fuse. Slow blow will have a coil of wire, spring, resistor or a combination of these three fuse elements. A Fast Acting fuse usually has a strait section of thin wire between the fuse contacts. White ceramic body fuses will indicate a "slow blow" or "time delay" on either the fuse body or around the connector ends. This is because the fuse element can't be seen inside a white ceramic body fuse.
Glass body fuses at or above 15 Amperes are usually rated for 32 volt circuits only. Ceramic body fuses (ABC type) at or above 15 Amps are usually rated for 250 volts. The ceramic fuse body (Fuse type ABC) can take the high heat and pressure caused by the arc across the open ends of the internal fuse wire at the instant the fuse activates or is blown. A glass body high current fuse might explode and cause a fire when its rating was surpassed (especially when the fuse is protecting a 125 volt or higher circuit). This is the reason glass body fuses are not made to operate under high current and high voltage conditions.

Important NOTE: Resettable fuses (house breakers, panel fuses, etc) are usually time-delayed type fuses and are not made to protect electronics.

Fuse polarization - Fuses are not polarized and work on Direct or Alternating Current. You can insert a fuse in either direction into its holder. Some very rare fuses have two different current/voltage ratings because Direct Current will produce more heat then Alternating Current. Usually about four times the heat. This is why metal welders work better using Direct Current.

Fuses act like weak points in an electronic circuit. Fuses blow so your game's electronics don't.

A typical fuse in a coin operated game will be rated in Amps, Voltage, interrupt time and fuse body type.

Fuse Example: 8A 250v SB AGC = 8 Ampere fuse rated at 250 volts interruption - slow blow/time delayed fuse type - long glass cylinder fuse body.
Typical Coin-Op Fuse Body Types
AGC 1.25 inch long glass cylinder fuse. This is the most common fuse body type for coin-op games. (see photo at bottom of question 24 on left)
AGX 1 inch long glass cylinder fuse. This fuse type is mostly used inside of switch mode power supplies and video monitors. Its short length allows it to fit in tighter places on circuit boards.
ABC or 3AB type fuse - Ceramic fuse body 1.24 inches in length, usually rated at 250 volts.
20 mm fuses are used on WPC-95 Williams pinball boards and sometimes in game monitors.

In the above fuse example, the most important spec is the fuse's current rating in Amps or Amperes (A=Amps). This is how many Amps of current the fuse can take before it will interrupt or open the circuit it is trying to protect from shorted loads or other high current draw faults (in coin-op - a bad transistor, integrated chip, shorted bridge rectifier, flyback transformer, solenoid coil, shorted broken lamp, shorted power supply capacitor, or shorted / burned connector).

Installing a foil wraped fuse is dangerous NOTE: A lot of games Pinball Medic has had to repair were "over fused" meaning the game called for a 10 amp fuse and a 20 amp fuse was installed by another repair shop or the game's owner. This is usually done because the fuse kept blowing. Instead of finding the cause of the over current draw, a fuse that can handle the maximum power the transformer or power supply can provide was installed. Overly large current rated fuses or fuses wrapped in foil can often not blow even if the load is completely shorted out. This condition can cause fires and/or burn out the transformer or power source. In extreme cases, aluminum foil was wrapped around a blown fuse causing the fuse to conduct again so the game could be played. This has the same long term effect as the "over fused" condition.

Excuse this Interruption: Fuses heat up and burn apart their internal elements when the rated current flowing through a circuit exceeds the fuse's current rating. Fuses act like weak points in an electronic circuit. Fuses blow so your game's electronics don't.
Fuses are rated for how much voltage they can interrupt when they burn themselves open. This can be visualized as the distance of the air gap between the remaining conductive components inside the fuse when it opens. The larger the gap the less likely the voltage across a blown fuse will arc inside the fuse and cause the circuit to be supplied with current even though the fuse has blown open.
To protect high current/voltage equipment use a ceramic body fuse. Glass body fuses can explode when they interrupt a high current load that is supplied with a high voltage (125 volts and higher). AGC fuses rated at or above 15 amps are rated for 32 volts only because there is little probability of a large internal arc when interrupting a 32 volt circuit. Ceramic body fuses are usually rated in the 250 volt range because they can handle the high heat and pressure caused by the arc across the open ends of the internal fuse wire at the instant the fuse activates or is blown.
Two Fuse Activation Times:
(commonly used in Coin-Op equipment)
A Fast Acting fuse will immediately blow open when the current the fuse is rated at is exceeded in a circuit. Speed in opening or disconnecting a circuit is important when protecting sensitive electronics inside of a game. The quicker a fuse opens the less time the electronic components are supplied with over current and the less chance they will burn themselves out. This is why fuses come in speed grades that are designed to protect very sensitive electronics. Ultra fast acting fuses are one type of specialty fuse that will open up a circuit in an extremely short period of time. Because the electronics in coin operated games are not extremely sensitive, they only require the normal operating disconnect speeds of a general purpose fast acting fuse. Ultra Fast fuses cost much more then a fast acting fuse and can be substituted for a fast acting fuse without doing any harm to a circuit in a arcade game. Ultra Fast fuses are not recommend only because of their higher then the normal fast acting fuse price. 1.25 inch long glass fuses

Fuzzy Fuses: Fuzzy Logic acts according to a linear instead of a binary logic function to better approximate and control "real world" conditions (a Digital A/C thermostat is an example of a fuzzy logic system). Instead of a pure binary two state logic (on or off, conducting or non-conducting), fuzzy logic systems work in a range of values and trigger points.
Fuses can be built in sort of the same style of fuzziness. They can be designed to trigger in a more linear fashion and only 'blow open' when a specific current range has been met for a set period of time (Watts/Time) and quicker if the over current is substantial).

A slow blow fuse is an example of a fuse that takes advantage of a timed (or fuzzy) burn out characteristic

Electrically tough components (relative to semiconductors, neon and dot matrix displays) like transformers, solenoid coils and light bulbs, require a different type of fuse then electronics. Coils and light bulbs produce a large inrush current when they are first energized. This is because non-activated light bulbs have cold filaments with low resistance to current flow. Solenoid coils don't have their cores inside of the coil form when first powered up causing the coil to draw more current then when the core has been pulled inside of the solenoid coil. Even large non charged capacitors in power supplies draw a heavy current when first energized. These types of variable current loads draw a lot of current when they first get powered on that can exceed a fuse's rating for a short time and would normally blow a quick/fast blow fuse.
This is where a slow blow or time-delayed fuse comes in handy. They are built to withstand a surge in current that exceeds the fuse's rating for a limited time before they burn themselves open.
This type of fuse is usually built with a coiled wire that heats slightly when a normal current is drawn through the fuse's load. If the load causes a large current flow for longer then a set time period then the fuse will burn itself out and protect the circuit. If the load should start drawing a very excessive amount of current (completely shorted load) then the slow blow or time-delayed fuse will act more like a fast acting fuse and burn itself out quicker then normal.
25. What types and sizes of cabinets are there and does the cabinet type add to a game's worth?
There are usually only four types of coin operated arcade cabinets. Full Sized, Mini, Cocktail and Cockpit.
Full sized arcade game cabinet Full Sized or Upright cabinet mini cabinet Cabaret or Mini cabinet
Cocktail cabinet Cocktail Cabinet cockpit Cockpit

The availability of a cabinet type and the popularity of the smaller cabinets can greatly influence the retail value of a game. Condition and rarity of a game title in a given cabinet style are usually major factors in determining a retail value for an arcade game.
A game's condition includes side-art, wood damage, monitor burn-in, playfield condition, control functionality, marquee, game board function and finally coin door condition. >br?

Cabinet Price and Availability

Full Sized or Upright arcade cabinet -
This is the most available style of cabinet and usually forms the base price for a typical coin-op game.

Mini cabinet - This smaller then full sized cabinet usually is rarer then the cocktail cabinet and usually are not worth as much as a Full sized game. They're not very popular for in-the-home arcade room use and therefore usually are less valuable then a full sized game.

Cocktail - This size is usually manufactured in half or less the number of full sized cabinets for a game title. They typically are priced much higher then their full sized brethren because they are both popular with the average game collector and are much rarer then the standard full size cabinet.

Note: People falsely believe that a Cocktail game takes up less space in a game room then a full size arcade. This is true in the vertical dimension of the game, but is not true with the floor space taken up by the game.
In fact, because cocktail games are usually two player and require playing the game by sitting at each end of the game, cocktails actually take up more floor space in a game room.
The cocktail cabinet does have its advantages over an upright game. They are played sitting down and are the easiest cabinet type to move around a game room. They also make great tables if the game is not working. Just cover it with a cloth and you have an instant table or TV stand.

Use Caution: Cocktail "tables" usually have a lot of scratches on the top glass. Metal objects can scratch even when a table cloth is used.
Sugary soda drinks make the inside of the game very hard to clean and repair.

Cockpit - Any game that must be crawled into to be played is generally considered a cockpit arcade.
They are widely considered the "Gold Standard" size of game by the advanced game collector as they are extremely rare. They command the highest retail value because of their rarity and because collectors with enough game room space for one of these cabinets typically can afford a premium game price.
An example: A full sized upright Star Wars color vector game might be worth $1400+.
A Cockpit Star Wars would be worth $2500+.
$3000+ if the cockpit game has the very rare 25 inch monitor installed. This was the only game to ever have a 25 inch color vector monitor installed in it and is considered by large game collectors to be the "Holy Grail" of all video arcade games.
26. What are the sizes of dot matrix displays (DMD) and are there any differences between display manufacturers? DMD pinball display tubeDot Matrix Displays (DMD) are usually used only on late model pinball games and some new amusement games (late model=1990 and newer pinball).

DMDs are measured in total dots per length (row) and width (column) and not dots per inch like video monitors screens.
Example:128 x 32=128 dots per row and 32 dots per column on the display tube.
WIDTH -- Dots per column LENGTH -- Dots per row.
NOTE: LED Dot Matrix Displays are now available for most games and don't require any high voltage to operate. They are now manufactured with a choice of colors or they can match the original display. Original DMDs are getting very hard to find and expensive. LED DMDs are about the only replacement choice.

NOTE: "Baywatch" and some rare late model pinball games use a 192 x 64 over sized DMD. A pinball with this unusual size display has a lower auction and retail price because of the very high cost of a replacement display.
It's not just the annoying background music on a Baywatch game that lowers its resell value. It's the great expense of the rare DMD that makes this game hard to restore.

DMD Prices - Prices on Dot Matrix Displays have gone way up in the last couple of years. It's not hard to find $400 or more DMD screens.
This expense should be taken into account before you buy a refurbished game if the DMD has not been replaced. The latest games are now being built with modern LCD or LED displays. This reduces the display cost and can add color and better animation to new pinball machines.

DMD or Dot Matrix Display usually come in three standard sizes or resolutions:

128 x 16 Length x Width Used on early "late model" pinball. This size is only sold as glass display tube only (no display tube driver board). The 128 by 16 displays are not compatible with 128 x 32 sizes as they have different connector wiring.

128 x 32 Most common size of DMD. Order the complete display assembly (display tube and display driver board) or be prepared to solder a lot of tiny display tube to driver board connections.

A 128 x 32 sized display tube has 4096 attached solder wires. This is why the whole display assembly is usually replaced because removing and resoldering all of these wires would take forever. Stern and some other pinball manufactures mount a separate display driver (logic board for the display) to a display assembly. This game specific display board will NOT come with a new display assembly and must be kept with the game.

128 x 64 Only a few games take this size and therefore this display can cost in the $300+ range.

Complete Dot Matrix Display assemblies include the display tube mounted to the display tube driver circuit board.

Pinball displays usually have a separate game display driver logic board that can be attached to the display assembly. This board is not included with a new display assembly and houses the game image data, display software PROM chips and a display micro processor (Z80,6800).
27. Are there different Flipper bushings and what can worn out bushings do to the playfield?

Flipper Bushing Types
Click on the photos to expand and view bushing dimensions.

03-6014 and A-2408 flipper Bushing 03-6014 and A-2408 - Williams nylon flipper bushing used on all games from
Post Time (04/69) to Laser Ball (12/79).
Williams Part Number - 03-6014.
Gottlieb Part Number - Gottlieb A-2408.

545-5070-00 bushing Stern/Sega/Data East #545-5070-00 - We are not 100% sure this bushing is used on all Stern games.
Older Stern and EM Stern pinball games probably use the 03-6014 type of bushing. The 03-6014 offers the longest through the playfield bushing length and the highest flipper to playfield clearance.

03-7568 Flipper Bushing 03-7568 - Used on all Williams pinball machines from 1980 to 1999.
Used on all Bally pinball machines from 1989 to 1999.
Williams/Bally Part Number 03-7568.

Worn out or the wrong type of Flipper bushings cause "flipper scrapes" .
Check to see if your flippers ever contact the playfield or wobble when moved with your hand. If they do then replace both flipper bushings immediately. Badly grooved or worn through to the wood "Flipper Scrapes" caused by the plastic flipper or its metal mounting bracket can't be refurbished.

Often route people and other repair shops install the wrong bushing type for the pinball they are working on.
Check and double check the flippers to make sure they have enough clearance between the flipper and the playfield. Playfield damage caused by flipper movement can be prevented, but not restored.

Always Check your flipper to playfield gap before playing a game.
Compare your old flipper bushing length to the new bushing before installing.

NOTE: The following games have not been completely verified to use the 03-6014 or A-2408 bushing.
Post Time, Suspense, Smart Set, Paddock, Expo, Roto, Set Up, Seven Up, Gay 90's, 4 Aces, Jive Time, Rock 'N Roll, Aces & Kings, Strike Zone, Straight Flush, 3 Jokers, Dipsy Doodle, Solids N Stripes, Doodle Bug, Love Bug, Gold Rush, Jackpot, Klondike, Planets, Yukon, Zodiac, Stardust, Yukon Special, Olympic Hockey, Granada, Spanish Eyes, Honey, Winner, Super Star, Big Star, Fan-Tas-Tic, Swinger, Travel Time, Fun-Fest, Summer Time, Match Race, Gulfstream, Tropic Fun, Jubilee, Skee Skill, Darling, OXO, Star Action, Tramway, Triple Action, Dealer's Choice, Skylab, Spacelab, Strato-Flite, Super-Flite, High Ace, Lucky Ace, Star Pool, Satin Doll, Big Ben, Pat Hand, Valencia, Triple Strike, Black Gold, Little Chief, Toledo, Space Mission, Space Odyssey, Aztec, Blue Chip, Grand Prix, Liberty Bell, Big Deal, Hot Tip, Lucky Seven, Rancho, Argosy, Wild Card, Hot Tip, Road Champion, Lucky Seven, Contact, World Cup, Disco Fever, Pokerino, Phoenix, Flash, Stellar Wars, Rock 'N Roll, Tri Zone, Time Warp, Gorgar, Laser Ball.
28. New reproduction versus old original backglass/scoreboard glass. New and used backglass score board glass differences

Pinball Medic cannot find a backglass/scoreboard glass for your game. The only spare ones we have will be on one of the coin-op parts pages on this site.

NOTE: Glass expanses and contracts at a different rate then ink and therefore a silk screened backglass should be kept in a temperature controlled area. Otherwise, the glass expansion will cause flaking over time.

A Backglass reproduction company will silk screen a new score/backbox game glass in batches. They don't make any more batches for a specific game title until there is enough demand to financially be able to make another batch. The time between batches can be months or even years if there is not much demand.

Ink flaking can only be partially stabilized on an original backglass. The coating process applied to the inked side of a scoreboard should only be attempted on a glass that is not too far gone or when a replacement glass cannot be found. Coating increases the backglass inks likelihood that it will be sensitive to temperature changes because any clear coating will have a different expansion rate then either the glass or the silk screened ink.

Using a new backglass versus an original is mostly a game owner's prerogative. If there is a good used glass that is not too far away (shipping costs on inked glass is very, very expensive), then yes, use an original glass. It will match exactly in color and image quality and tends to look like it "belongs" on the game. The hues and age of the ink will be the same as the rest of the game.

A new score board glass can be so much easier to find then the original and issues like ink flaking will normally not be a problem with a new reproduction backglass glass (any ink will flake off glass if it is subjected to extremes in temperature variation). However, new replacement glasses use newly formulated inks that might not completely match in color. The ink or the reproduction process can be too good in quality to appear on an old electromechanical game. Game buyers know red, pink (pink used as a flesh color) and other hues classically peel away from the backglass of certain years of games. The inks used back then were not formulated correctly for longevity. They will peel with age.

Pinball Medic always prefers and strives to use original parts whenever possible or will indicate otherwise before a game is sold to someone.

Game Pricing Note: "Pinheads" can usually tell the difference between an original and a reproduction backglass. They don't usually like a game with a new backglass. A copied backglass can affect the final asking price or game value on a refurbished pinball or arcade when dealing with some advanced collectors (a pinhead). Some casual home use customers will not be able to tell the difference between a new and used backglass. Most don't know if it should be made from glass or Plexiglas. We try to educate them about this if we are selling a game with a replacement score board glass.
Physical Glass Differences:
A new glass may not totally match the original in color, be too shinny or have artwork design errors. These "errors" can be caused by the scanning method the manufacture used or the condition of the original glass that was copied. Most master copies are done by hand and then a silk screen is made for each color in the image.
Computer scanners are becoming sufficient enough to be used in the reproduction process. The image in this case is cleaned up using an image editor program. The silk screen master is then printed digitally. There is no current way to scan a scoreboard glass that uses mirrored sections (mirroring usually scans as black). This is why some modern backglasses are not available as reproductions.
Errors in reproducing the exact image can occur during any step in the copying process. Scoreboard glass reproduction manufacturers can also intentionally make the image slightly different so they can tell an original from their copy. They even will produce plastic versions to make the reproduction process and the shipping costs much cheaper. They often will not bother to offer a glass option when they print on plastic.
The buyer must be aware of any physical differences as the manufacture will not volunteer this information. Ask some questions before ordering a backglass for your game or be prepared to be surprised when it gets to your home/business.
29. Line voltage and the dangers of "high tapping" an arcade game.

Line Voltage -
The voltage supplied to a game measured at the wall plug or output voltage of a line voltage converter box.

Normal Line Voltage - A line voltage that is neither too low or too high and equals the designed operating voltage for the game.

High Tapping - Changing a tab / lug or a power line connector on a transformer to compensate the secondary voltage(s) supplied to the game by changing the primary to secondary coil winding ratios of a transformer. This process is usually only done to compensate for low or high line voltages but has been used on games with normal line voltage levels for nefarious reasons.

High Tapping on Modern pinball games is usually done by changing the wiring of a connector, a selector switch. The main fuse (line fuse) must be changed to usually a higher amperage fuse when converting from the standard 220 voltage of some European countries to the standard 120 volts used in the USA.

EM pinball uses a soldered on transformer tap/lug or the changing of a fuse position on a fuse holder to compensate for a low line voltage only. If an EM arcade game was originally shipping overseas then usually the transformer will need to be changed out to convert back to the normal USA line voltage.

Step-Up Transformer - A transformer with more windings on its secondary then on its primary winding coil. This type of transformer is used to increase the voltage supplied by a transformer.

Step-Down Transformer - A transformer with less windings on its secondary then on its primary winding coil. This type of transformer is used to decrease the supplied voltage of the transformer.

Any output or secondary winding voltage from a transformer can be calculated using the difference between the Primary Winding and the Secondary winding wire turns ratio times the input voltage or in this case the Line Voltage.
Transformer Parts Descriptions:
Photo shows a transformer with soldered on lugs for voltage adjustment or High Tapping

Note: Only an Electromechanical game transformer is shown in the photo as they use a wire tap change to high tap the transformer. Modern day electronic games use a connector that can be re-wired for high taping purposes. Transformers and their power connectors very from game to game so we will not be presenting a "how to high tap" procedure.
More WPC transformer info.

transformer lugs or taps for voltage adjustment and high tapping an coin-op arcade game including pinball and video games Primary Coil - This coil or wire windings can be considered the input to a transformer. It is usually supplied by the game's power cord at line voltage through a spike arrester, EMI (line voltage) noise filter and power turn-on switch. This voltage normally measures 120 volts at 60 cycle Alternating current in the USA and can measure 220/440 Volts 60/50 cycle AC in Europe. There can be one primary coil with a number of different voltage level adjustment taps or two or more Primary coils that are either connected in serially to adjust the transformer's turns ratio between the Primary and secondary coil(s).

Secondary Coil - This transformer coil or coils produce the output voltage(s) to the loads the transformer is powering. There can and usually is many secondary coils producing a number of different voltages.

Transformer core - The metal body of a transformer used to transfer electromagnetic force between the Primary winding and the Secondary windings.

Power supply or transformer load - Any part that is supplied power by a transformer or power supply board including coils, bulbs and electronics.

Pinball Medic can't describe the actual process of changing the voltages supplied by a game transformer. This process is different for each specific game. Consult the Game's manual for more information. What we present here is the effects of High Tapping a game.

Coin-Op games are designed to operate in the USA and in Europe. Most countries use a different line voltage and even frequency then the U.S.A. Therefore game transformers and power supplies have to be designed to operate at different input voltages but still provide the the same output voltage.
Low Line Voltage can be caused by a multitude of reasons involving distance between transmission line transformers, house wiring wire diameter, etc. Game designers therefore included a method to change the transformer's primary to secondary windings ratio to compensate for low and high line voltage and to convert a foreign country's line voltage levels to USA line voltage levels.
High Tapping a Transformer
High Tapping is the method of changing a transformer's winding ratio by the means of de-soldering and changing a soldered wire tap/lug on the transformer, changing the wiring of a connector, changing the position of a fuse or selector switch or socket.
By changing a tap you are changing how many windings are used on any given coil and therefore the ratio between the Primary and Secondary coils. Changing this ratio produces a change in the output voltage of the transformer, but only if the line voltage were to remain a constant (at the normal line voltage).
If the line voltage is low and you decrease the number of wire coil turns on the primary, the secondary coil voltages will increase and produce the same voltage output as if the line voltage was normal. The same occurs if wire turns are added to the secondary coil by means of changing a transformer tap.
The Primary coil tap change method of coil ratio adjusting is also used to convert a higher or lower input or line voltage and allows an arcade game to function on different line voltages from different countries. When converting from one country's voltage to another only the number of primary coil windings is adjusted. This is because adjusting the primary coil will increase or decrease all of the secondary coil's output voltages.
Effects of high tapping a normal line voltage game.
High tapping normally does not effect an output voltage of a transformer. This is because normal high tapping is used to compensate for a low or too high of a transformer input or line voltage.
If primary coil high tapping were to be done to a game with normal line voltage it would increase all the output voltages of the transformer. Increasing the 5 volt logic, relay or solenoid coil voltage, light bulb supply voltage and even the display voltage.

Modern pinball games (90's and newer) are somewhat "safer" to high tap then a middle aged (70-80's) game because of improvements in voltage regulators and power supply designs.
Some Electromechanical (EM) games can handle an abnormally high tapping because unlike solid state games, usually only the relay and solenoid coil supply voltages are changed (secondary coil high tapping). Although, the more dangerous primary coil high taps can be present on an EM game.
High tapping should normally only be done to change a low or high line voltage and not to improve the playability of a game.
If you can't play the game as it was designed then it's better to change the flipper coils then to overpower every coil in the game.

Differences between changing a tap on the primary or secondary coil of a transformer:

In electromechanical games a tap is usually provided on the secondary to change only the solenoid coil and relay voltage.
For example: high tapping a typical EM pinball game only raises the 50 volt (solenoid power supply) secondary coil to 55 volts if the line voltage is normal. High tapping is usually only done when the line voltage is low to bring the secondary voltages back to reading normal voltages, however, High Tapping is often done to increase flipper and all other solenoid strengths or to temporarily prevent a game with normal line voltage from resetting due to old defective capacitors in the power supply. This kind of normal line voltage high tapping "hack" should not occur. The game should be repaired instead.
Nerdy Note: A transformer core is usually made out of laminated thin sheets of metal to reduce eddy currents inside its core and to increase the transformer's electromagnetic transference efficiency.

Why would anybody high tap a normal line voltage supplied game? The reasons are numerous and nefarious.

To increase the flipper strength to make a ramp shot or other skill shot easier to make. Game owners often complain about weak flipper strength. Very few games have been designed with too weak flipper coils. The usual causes of weak flippers are dirty, mal-adjusted or damaged flipper mechanisms. These are all mechanical problems that people are trying to fix with a voltage adjustment. It is better to simply repair the problem then to risk every coil in the game just to get a little more power from the flippers.

If you must have stronger flippers without the added strength to all other solenoid coils then rebuilding the flipper units or installing a flipper coil with one that has fewer number of turns of wire on the first set of coil part numbers is the preferred way. Just don't install way too strong flipper coils or risk damaging a flipper bat or other playfield plastic part.

B) Pinball Games with a large number of heavy current draw (strong pull in strength) solenoid and magnet coils often reset themselves right in the middle of a game or when a multi ball session has started. This is because one power source (the coil power supply in this case) can lower the voltage output of all power supply voltages if only one is under stress (power supply with a large load or current draw). The common component to all pinball power supply voltages is the transformer. If the transformer is not built with enough of a core (not many arcades have a large enough transformer), then high loads can effect the outputs of the transformer.
Capacitors inside power supply boards are used to compensate for momentary voltage fluctuations caused by heavy power supply loads. These capacitors are usually over 20 years old and can't keep the supply voltages stable. Bad capacitors, bridge rectifiers, voltage regulators and burnt connectors are what usually cause games to reset during play. Twilight Zone is an example of a game that can often have a reset problem due to the number of playfield coils and old capacitors/connectors/regulator.
Again, some people think that by High Tapping a normal line voltage supplied game they can somehow repair a resetting game. What they should have done is to simply replace the old large electrolytic capacitors and bad connectors to repair the game. Increasing all the power supply output voltages by an abnormal high tapping can cause the electronics, solenoid and relay coils and just about every other electronic or electrical game component to go bad over time.

C) We have talked about connectors before, but, they are so important that we will provide additional information on them.
Connectors whether being the wire connector or electronic board connector variety are not made to last forever in fact most board connectors are only designed to be disconnected and reinserted only a very few times. Many of them are under speced when they came from the pinball factory. This was done to save $20 a game and has often caused repair men hours of troubleshooting. If there is a design flaw in all arcade games them connectors would be this fault.
Burnt up connectors produce a high resistance connection (if they connect at all) and either don't pass all the current/voltage to their loads or because of dirt and other contaminates heat up and start to go bad. General Illumination (G.I. lights) connectors are often prone to self destruction because they normally have too much current flowing through them and are very old.
Connectors with a high resistance connection don't pass all the voltage and current of a new clean connector and therefore produce symptoms like dim G.I. lighting, weak solenoid coils and game resets. By increasing the output voltage of a power supply by high tapping the high resistance connector can be partially compensated for its voltage dropping resistance. This can brighten up dim displays and lights and can even help to prevent game resets at the risk of burning up every other electronic part in a game.

D) Because I can! High tapping is a very cheap and unskilled way to temporally "repair" a game without having to troubleshoot or replace any bad parts. This allows for a fast turnaround or flip for game salesmen and because the damage can take awhile to occur, a field service call can be done after the warranty has expired. This provides illegitimate repair shops an extra source of income.
High Tapping is also permanent unless the wire tap change is undone. Many people buy an non-working game to save money and do a very good job of repairing it just to have the same board or part go bad because the game had been high tapped. Replacing a bad connector and then forgetting to change the transformer taps (adjusted to compensate for the bad connector) has often been the demise of a lot of good games and game parts.
Always check to see if a game has been "HIGH TAPPED" before plugging it in for the first time. This is a common occurrence.
Repairing a game is always better then an abnormal high tapping.

30. What methods can be used to fix weak or non operating flippers?

end of stroke switch and flipper unit wire diagram End Of Stroke (EOS) switch and flipper unit wiring diagram.
NOTE: The EOS switch is at the bottom of this photo. The End of Stroke switch can have a capacitor connected to it in some early pinball games. This capacitor will come with the rebuild kit.
A flipper activation switch can be attached to the EOS switch on flippers near the outhole in certain games to activate an upper playfield flipper. This switch should not be confused with an EOS switch.
EOS switches can also be used to 'tell' flipper driver electronics that the flipper is at its end of travel position (fully upright). The flipper drive electronics can then supply the coil with a lower voltage and prevent flipper coil destruction. In this case the EOS is usually a small contact switch that is not meant for high current coil kick back operation.
See our Pinball Restoration Process for more EOS switch details.

A typical early model flipper rebuild kit Typical Flipper Rebuild KIT parts
One Kit has enough parts to rebuild two flipper units.

Rebuild kits are ordered by game manufacturer and the date the game was made. This determines the type of linkage, return spring type, and coil stop. Not only can a rebuild kit repair a weak flipper it can also completely rebuild two flipper units with just one kit. At a cost of usually about $35-40 per two flippers, these kits are truly one of the cheapest ways to improve game play and extend game playfield preservation.

The solenoid plunger and the flipper linkage claw are both problematic parts on a flipper mechanism. When replacing these parts, make sure there is enough of a gap between the claw and the bushing or the flipper can bind or sometimes bend the flipper shaft causing the flipper bushing to wear out prematurely. This will cause flipper scrapes or a flipper that never reaches its full travel range. A mechanically binding flipper unit is one of the fastest ways to overheat a flipper coil.

Flippers are some of the longest activated mechanisms on a pinball game. They have to be both powerful when moving the flipper bat and strong enough to hold the pinball game ball(s) when fully upright without burning up the flipper coil. Their coils can be complex. Often flipper coils use two coils of wire on one solenoid body or one coil using very complex driver and trigger board electronics. Unfortunately, they are not an assembly that gets any maintenance until they do damage to the playfield or are so weak (or not working) that repair becomes mandatory.

Flippers are just as influential to game play as the game ball and the game's design. Flippers and playfield maintenance are often blamed for the decline of the pinball game in Coin-Op Arcades because so often arcade games were left too dirty or poorly maintained to play.
Williams (of Williams pinball Inc fame) complained about route operators not taking care of "his machines" . According to him, everyone stopped putting quarters into pinball games because they were so dirty and often had non-working flippers. The game became non playable and regular players became discouraged.
A lot of pinball collectors think he had a point, but, also blamed it on the design of new pinball games getting so playfield toy orientated and having very high point scoring targets. Instead of using the more classical playability/fun games designs of years past.

Luckily for everyone, parts and full flipper assemblies are still being made for most classic and newer pinball games.

Fixes for Weak Flippers

Just the plastic bushings can be replaced to repair some flipper units, but we highly recommend installing a flipper rebuild kit along with new flipper shafts and flipper bat plastic to a weak flipper assembly. A flipper rebuild kits replace all of the other probably warn out flipper unit parts like the coil stop, coil plunger and linkage, flipper claw, end of stroke switch with capacitor and the return spring.
The only parts not replaced by a rebuild kit are the flipper body flange, the plastic playfield through bushing and the flipper coil. Flipper coils and bushings are different for just about every pinball game and flipper body flanges come with new flipper units only.
Old (EM) to middle aged (early SS) pinball games usually have a normally closed flipper unit 'End Of Stroke' switch (EOS, this switch is shown on the bottom of the full flipper assembly photo). These switches are the most common flipper component causing weak flippers next to things like a burned out coil and dirty flipper plunger core. These parts need to be cleaned and re-adjusted periodically to maintain a good flipper strength. The End Of Stoke switch is the only switch other then an old model flipper button switch that can be cleaned with a small metal file. They have solid Tungsten contacts (or gold plated - do not clean this type of contact with a ignition file). They are often pitted and burnt causing the switch contacts to have poor conductivity and thus cause a weak flipper. Capacitors are often attached "across" (in parallel) with the EOS switch to dampen the "coil kick back" inrush current every time the EOS switch opens. EOS switches short out the large number of wire turns 'holding' coil on the flipper solenoid coil till the flipper almost reaches it's fully raised position.
When open, the EOS switch allows current to flow through both the holding coil and/or the high strength coil. This adds a great number of total turns of wire on the solenoid coil and allows the flipper to be activated indefinitely without over heating. If the EOS is dirty, mal-adjusted or just not making a connection then the flipper will appear to be very weak. The EOS switch needs to be adjusted so it opens about 1/16 of an inch wide when the flipper is at it's most upright position. If this switch opens too soon (too wide of a contact gap) the flipper will never reach its full strength before going into "holding" mode and will again appear weak. If the EOS never opens then the coil will overheat and burn itself out.A typical full flipper assembly

A typical full flipper assembly with body bracket (Flipper Base)

New Flipper Assemblies

The majority of the time a flipper bushing, flipper shaft and rebuild kit is all that is needed to make the flipper work like new again. However, there are lots of times when these consumable parts just are not enough. This is when a new full flipper assemble is required. A new assembly comes with everything a rebuild kit has with the addition of a mounting body bracket, sometimes the flipper bushing and even the flipper coil. One new flipper unit usually cost about the same as a rebuild kit. Stripped out screw holes in the metal body or for a flipper upgrade are reasons for having to replace the whole flipper unit. Also common is having to replace a flipper unit assembly on a game that no one makes a rebuild kit for or the same flipper assembly type. It is common to see an old style Williams pinball flipper unit on a old Stern or Bally game because it is so hard to find a coil stop for certain model years. These hard to find coil stops have mounting holes that are way too close to each other and tend to break between the holes or all the way across the bottom flange of the coil stop.
New flipper units must be ordered as a Right or Left side unit as there is a difference in the claw that holds the flipper linkage to the flipper shaft. Each new flipper assemble should come with a new flipper coil and bushing however, some suppliers make you order these parts separately.

Upgrading a flipper assembly
From time to time pinball manufacturers made improvements to their flipper assemblies to either stop them from wearing out so fast or keep them from mechanically binding or jamming.
In the good old days of EM pinball games, a return spring was used that had a small diameter end on one end of the spring that was about the same diameter as the solenoid plunger that ran through the spring. In time, the spring would try to go through the same solenoid support bracket that the plunger does causing the return spring to eat through or jam the plunger and stop it from moving freely. After only about 20 years, pinball builders finally figured out to move the return spring to a separate flange on one end of the spring and to connect the other end to the linkage claw and to use a spring that had the same diameter the entire length of the spring.
These improvements mint the return spring never interferes with the movement of the solenoid plunger and made the flipper unit last a lot longer. These new improved flipper units can be installed on most Electromechanical and early model solid state games as a 'flipper upgrade' to improve the functioning and longevity of the flippers. However, Pinball Medic either rebuilds or replaces the flipper assemblies with the same style and year part that was originally installed on the game. We want to preserve as much as possible the original operation and game play of any pinball we work on. So what if the flipper units will need a rebuild kit every five to ten years of normal play. They will probably be dirty and weak by then anyway. Also, if the game is constructed with same year parts, then only a limited number of spare parts must be kept around the game to keep it playing. It's just like putting a black rubber ring kit on an EM pinball to use modern full flipper units on an old pinball. Both the rings and the new flipper units would not look right to a trained game technician and therefore we think they don't belong on this style and type of pinball game.
31. Types of Playfield Lockdown Bars.
Pinball Playfield Lockdown Bars are used to both keep the playfield glass from sliding off the game and as a hand rest while playing the game. They are usually made of stainless steel and are game manufacturer and era specific. A Bally bar will not fit on a Stern pinball and an early Stern lockdown bar will not fit a modern Stern game.
There's an obvious lockdown bar difference between wide body games and standard width games. There are playfield width differences between manufacturers and even differences between older wide body games and newer wide body games from the same game manufacturer.
The "Beer Seal" is in most photos and functions to keep beer (because no other liquid could possibly be spilt on a pinball playfield glass) from entering the game. It is usually made of a rubberized foam material and can be bought at a hardware store if a replacement is needed (closed cell weather stripping foam seals work best).
We will now provide some photos of a few lockdown bars so you can see their differences and know what kind of bar you need for your game. Only the 1990 and newer Williams and modern Stern pinball game lockdown bars are being manufactured today.
The following information does not indicate our current inventory of lockdown bars. In fact, Pinball Medic does not have ANY new or old lockdown bar to sell and probably never will as we must keep any spares to use on our games to refurbish or to sell inventory.
Williams 80's pinball lockdown bar bottom view Williams 1980's era playfield Lockdown Bar (bottom view with beer seal at the bottom of the bar).
This type of playfield glass lockdown bar was used on games like 'Gorgar', 'Firepower' and 'Flash' pinball games.
Williams wide body pinball lockdown bar

Williams 1980's era Wide Body (Super Pin) Lockdown Bar.
Stern 1980's Pinball Lockdown Bar

Stern 1980's era Lockdown Bar.
Fits EM's like 'Memory Lane'
Bally 1980's pinball lockdown bar

Bally 1980's era Lockdown Bar.
Used on games like 'KISS', 'Playboy' and 'Centaur'.
32. Why can't Coin-Op repair shops fix home version pinball games?

A Home Version can be defined as a game without a coin door made to be played in a private home and not on a commercial arcade site.
The 'home version' is different then a console video game that connects to an in the home television. It can't be considered an arcade game either because they were never designed to be in one.
Some examples of home version games made by Bally are in the photo below.
Notice they don't have coin doors and are built with half the normal pinball cabinet depth.

Trivial Note: The Fireball home model pinball machine was also sold as a "kit" by Heathkit (# GD-1110 Pinball Game).
Home use only games
Realizing a few adventurous people may want to try and repair their own game (power supply board can sometimes be repaired) and because Pinball Medic has no intension of ever repairing a Home Version game (These games have no or little retail value - $200.), we have provided a repair manual for both of the Bally home version pinball MPU systems (7.2 Megs).
Good luck!

(12-28-15) There is now a little hope for the Bally home version pinball game owner. The CPU board is being remanufactured or at least in the design phase.
A redesign the power supply boards as some versions use the printed circuit traces as a fuse. There are 4 different versions of the
series 1 power supply (ver. a,b,c,d).
There is going to be replacement power supplies and MPU boards made for these home use games. More information is on an external forum page and on page 3 of our Tech Tips pages.
Bally made the vast majority of games for the Home Version market. They where intended to improve Ball's bottom line and allow them to make a cheaper version of their popular full sized pinball games for home use. Retail stores could now sell games instead of the Coin-Op game distributor being the only source.
They were never very popular and therefore not many are working today. In fact, it usually takes two games to get one working because the circuit boards are no longer made.

Home Use only games do not share any circuit boards with their full sized pinball brethren. To make things worst, Bally used a very unusual MPU chip with an onboard ROM program. If a repair shop had the image for this ROM. It would be cost prohibitive to buy the special chip programmer to burn the software into the MPU chip to only repair a few home version games. Also, this special MPU chip is no longer manufactured. Unavailable spare parts for these games makes them non repairable for coin operated (Coin-Op) repair shops.

The only good part about these games is they use the normal full sized pinball game playfield of the classic game they represent. Playfield parts other then plastic sets are therefore obtainable and playfield repair can be accomplished. They don't however use the same backglass, score displays or circuit boards as regular full sized pinball games, so only parts off another home version game, of the same game title, can be used to repair another game of this type.

This is a list of Bally home version games.

Series I:
606-1000 Fireball, 614-1000 Evel Knievel
614-3000 Fireball

Series II:
614-2000 Captain Fantastic, 614-4000 Galaxy Ranger
614-5000 Fireball
33. Why would someone wax a playfield and what wax would they use?

pinball playfield wax A wax with a high melting point (a very hard wax) is what is used to protect a pinball playfield from game ball roll, dirt and water damage.

Carnauba wax is a good choice as it is easy to get as a car wax and is hard enough to last through many hours of game play.

Waxing a playfield more then one time just wastes wax and labor because even with a 100% carnauba car wax, there are still enough solvents in the wax to remove the just applied wax layer off the playfield.
100% carnauba wax (food grade) is hard as a brick and can be found in wood working shops. It is too hard to work with in this form.

Waxing playfield plastics can be done. Plastic playfield parts should be cleaned when ever a new rubber ring kit is installed or every other time game balls are replaced. Clear plastic ramps are not waxed as the ramp can turn yellow over time.
Pinball Medic will not wax playfield posts or other playfield plastics because they are taken off the playfield too often and cleaned to warrant putting wax on them. Also, waxing a dark colored plastic post (with grooves or fins) and non glued on protective mylar plastic (under pop bumpers) produces just about the ugliest looking part on a playfield. This is why they need to be removed before any playfield waxing is started.

NOTE of the OBVIOUS: Carnauba is a wax used in wood working and as a "food additive" in cheap chocolate bars. It smells great right out of the can, however, you should never try and eat car wax! Yum, paste.
To Wax or not to Wax
Waxing a playfield helps to protect very old wood playfields (mostly Electromechanical pinball games) from a defective game ball's roll damage, playfield dirt and wood dry rot (if rot is not present). It can also provide for a faster ball play without having to increase the slop of the playfield. However, it's a personal decision to wax or not to wax. Waxing a playfield is a very labor and time consuming process and happens after a total playfield cleaning. If done correctly, all playfield parts/plastics, except pop bumpers, must be removed before the wax is applied. Also, masking tape should be applied to any wood that is painted/inked with a dark color. Wax on dark color wood will leave an ugly white smudge that's hard to remove.
Wax can protect a playfield, but not if the playfield already has wear damage that goes into the wood under the playfield artwork or on dry rot cracks. Waxing a worn out playfield will make it look worst before the wax. Wax will turn white around and into the damaged area. It's too late to protect a damaged playfield with wax. Also, a wax layer will prevent any playfield artwork touch up or clear coating. The wax must be removed before the playfield artwork can be refurbished/restored.

Carnauba is a good wax to use as it is readily available as a car wax. Only 100% carnauba paste car wax should be used as most liquid and other car wax types have been diluted by "cleaners/solvents" . When using a carnauba paste car wax, there will not be any build up or layering of the wax between applications. Even a "100%" car wax has enough solvents in the wax to remove the previous wax layer as you apply a new coat.
Game balls should never be waxed. Instead, they should be replaced often with good quality mirror finished game balls. More info on wax types, how to apply and remove wax and other helpful tips will be provided in greater detail on another QnA.

Pinball Medic uses nothing but the wax in the photo on the left. One tin should last a game collector a lifetime as our shop's can of wax has lasted for over five years and we haven't even come close to hitting bottom yet.
Is it the best possible wax to use on a game? Probably not, there are synthetic waxes ($50 and higher costs) with higher melting points that may or may not remove playfield artwork. The special purpose waxes can be bought for a very high price at a good car detailer, however, carnauba is the easiest to buy from a car parts store and the one Pinball Medic uses is almost a pure wax with low levels of solvents. It also smells really good.

A soft clean 100% cotton cloth or even a new all cloth diaper is what is used to apply the wax (A clean cloth pad or applicator will work.). However, before the wax is applied, the playfield must be cleaned and stripped of all plastics and ramps. Plastic ramps are not waxed as a waxed plastic ramp will turn yellow over time. Metal ramps can be waxed as long as all excess wax is removed.
In addition, all bare or dark colored inked wood (dark colored playfield side rail wood, etc.) that you don't want to have white streaks on, must be taped off with a good quality masking tape. This step is seldom if ever done by other refurbishment shops or even game collectors. A good hard WAX is hard to remove, so why would not stop it from showing on playfield parts that shouldn't be waxed? By removing the playfield plastics (and bulbs), one can apply a thin wax coat under the plastics to help protect even hidden areas from water damage and dirt.

Wax is mostly applied to old but in good condition EM pinball games. It is also perfectly safe to apply this same wax to "diamond plated or hard coat" playfields. The wax we use is safe for these late model playfields and will slightly speed up the ball play when compared to an unwaxed playfield. Just make sure the wax you use is safe for a "clear coated car" and it should be OK for a "coated" surface playfield. It's practically the same coating.
34. What kind of oil can be used on arcade game motors and pinball leg level adjusters?

blue oil can Using the wrong oil can cause non-replaceable parts to be destroyed over the lifetime of a game. The application of the wrong lubricant on some motors can not be undone because the felt oiling pad cannot be removed or replaced.

3n1 Oil NOTE: The BLUE inked can in the photo on the left is OK to use on arcades, but not the RED colored can!
The 3n1 BLUE colored oil can shows an image of a motor and the words "motor oil" . Both are on the front side of the container.
Paraffin wax (red can) based lubricants should be avoided!

Wax based "oil" can harden, will cause jamming and a lack of motor armature lubrication over time.

NOTE: Never oil slide contacts with any type of oil.
Slide contacts are on stepper units, vari-targets, score reels, swinging targets and other EM and SS pinball parts. They were all designed to work dry.
Never oil plastic game parts or Simon Peter will put you into Purgatory.
This and greasing any plastic game parts is a serious coin-op SIN!

We charge a fee to get rid of it and replace the plastic parts!

Copper and brass are self lubricating metals. Meaning they are designed to operate dry and never need lubrication.

Pinball Score Motor oiling felt hole The Three N One can's color has a lot to do with the kind of lubrication in the can. The very common RED can is made with a paraffin wax based lubricant. While the blue can (see photo) contains actual petroleum distillates (oil) and is made to be applied to motors and non electrical (not on switch or stepper unit slide contacts) metal parts.
Only a few drops of oil are ever needed and should only be applied about once every decade unless the game is prone to rusty leg adjusters. Also, A very dry environment can cause oiling pads to dry out requiring more oil to be applied.
Lube types and what lubrication not to use.
NO OIL or Grease is ever used on anything plastic on an arcade game.
However, there are a few metal parts and a motor oiler felt that will require oiling a few times in the lifetime of the game. "Three N One" oil is a common and easy to find lubricant. It is sold just about everywhere in the USA and can be found in hardware and even grocery stores.
The problem with this is most stores only supply the RED colored can and not the BLUE inked or colored oil can in the photo on the left.

What does the color of an oil can have to do with the lubrication of my game?

The 3 N 1 can's color has a lot to do with the kind of lubrication in the can. The very common RED can is made with a paraffin wax based lubricant. While the blue can contains actual petroleum distillates (oil) and is made to be applied to motors (only to the oiling felt). Don't oil the plastic or copper/brass motor's gears. They are designed to run dry.
Paraffin is normally a semi-hard wax and must be mixed with solvents to produce a liquid base for a lubricant.
When ever the solvents evaporate, the wax will revert to its natural semi-hard state.
Note: The normal car "oil" is based on paraffin wax.
If a wax based lubricant is used on the felt lubricator of an EM pinball Scoremotor or on a swinging target motor, it will lubricate the armature barring for a short time and then harden. This situation not only stops the lubrication of the barring, but stops any absorption of additional oil put on the felt. The wax cannot be removed because the oiling felt pad cannot be removed from the motor or replaced..

Petroleum "Jelly" is not a lubricant but does find it's way onto arcade parts from time to time.
Never apply this jelly or expect being charged a grease removal fee when the game is refurbished or repaired.

Note: Some game refurbishment shops will use a Teflon based spay, wiped on "contact grease" or oil. This practice will fail in the near future and indicates the refurbishment was not done correctly.
Infact mix grease with oxigen and you get a fire! This is why oily or greasy rags can light on their own! If a greased slide contact sparks, it can start the game on fire! Pinball stepper units are designed to never need lubication!
EM and SS Pinball Lubrication Guidelines
1. OIL, grease or graphite are never used on anything plastic inside or on an arcade game.
2. No lubrication can be used on stepper slide contacts.
3. Car motor oils can not be used
because they contain too many additives and are usually based on wax. Most car oil additives are good for the car's engine but will harm a small electrical motor or simply dilute the effectiveness of the oil already applied to the motor. Also, most car motor oils are again based on wax as it is much cheaper then real oil. Synthetic oils can provide much improved heat resistance and lubrication factors. However, their great expense usually out ways their lubrication benefits.
4. Never use any form of a wax based lubricate. Also, false lubricants like WD-40 and petroleum jelly should never even be inside of an arcade repair shop or on a game part.
5. Never over oil. Only a few drops of oil is ever needed. Excess oil can drain out, be hard to clean up and get on something that doesn't need oiling like a switch contact. Most parts in both EM and Electronic Pinball machines or EM arcades don't need lubrication and can be harmed by oil or grease.