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

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

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

27. Flipper Bushing types demystified and flipper scrape damage caused by worn out bushings explained.

29. Line voltage and the dangers of "high tapping" an arcade.

31. Types and photos of pinball playfield lockdown bars

22. Do all pinball games use the same size of game ball

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

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

28. New reproduction versus old original backglass/scoreboard glass

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

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

"Play Pin" Coin Operated Game Forum pages.

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 21. Can an arcade game be left powered on all of the time? 

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.
Arcade Game manufacturers design a game to be powered on all of the time because they will be during their 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.

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.

• 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 burn out the bulb.

• Large electrolytic capacitors are like shorts 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 only happen for a short time, 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..

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 POWERING AN ARCADE GAME 24/7 

Leaving a game running will cause destruction to expensive game parts over time (monitors, power supplies and displays). We feel a game should only be left on as long as it is being played. The destruction of game parts over a long period of game operations time 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.

EM pinball:
• Heat generated by the general illumination lamps can warp playfield plastics and cause the ink on scoreboard glasses to flake.
Electromechanical pinball games usually are the most sensitive to plastic warping and ink flaking because they are all 30+ years old. Plastic durability and resistance to heat has improved over the years.
See Tech Question 1 regarding bulb type replacement to help prevent plastic and scoreboard ink destruction.

• 'Game on' relays, score/playfield motors, coin-lockout coils and any other part of an electro-mechanical 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.

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

• 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. The heat built up by G. I. bulbs can warp playfield plastics, marquees, coin slot pricing cards and other game specific parts. Light bulbs in playfield inserts that blink or don't burn for long don't build up heat, however, the always on EM pinball insert bulbs do and 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. However, we recommend changing out 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.
See Tech Question 1 for more information on bulb types.

  Video Games:
• 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.

• 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 in older video arcade games.
Older classic games do not have fans or more effect 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 (See Tech Question 5 for more info on monitor screen burn-in). Leaving a video game powered on all of the time speeds the monitor image burn-in process.

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 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 Que ball that is 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 ball1 Inch Ball - Used on only a few electromechanical pinball machines from the 1960's and on Bally TRUCKSTOP to improve ramp shot playability.

1 1/4 Ball - This is the oversize ball used in Gottlieb STRIKES & SPARES (14 balls required for this game) bowling style pin table.
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)
Used on roulette wheel in:
Gottlieb MONTE CARLO, Bally SPEAKEASY,
Williams MILLIONAIRE
Reference Williams part #20-6520

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 PINBALL GAME BALL SIZES    Return to Tip Index

Although most games use the standard sized game ball, some use a smaller diameter game ball. Smaller game balls have less mass 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).

Can a game be equipped with a smaller/larger game ball to multiply or decrease the games playing speed?

Maybe, normally you should not put a smaller size of game ball on a playfield designed for a larger ball. The game's main coils like flippers and pop bumper coils would be too strong for a very small game ball. The ball would probably get stuck under a playfield rubber ring and break some general illumination lights.

A slight increase in the game ball size can slow down a pinball game. A slight increase in ball size can be used to slow down or make a skill shot harder to get. Usually a standard game ball is placed in a game designed for a smaller ball to slightly decrease the number of free games caused by high scoring skill shoots. A larger ball makes the flippers weaker and therefore makes all skill shots harder to make.

The top of the ball must be checked to see if it will contact any playfield plastics that use shorter mounts for smaller game balls. If the ball ever hits the playfield plastics it will break them. Also, if the rubber rings are lower then on a full sized game ball pinball, the ball can lift up from the playfield and cause playfield artwork destruction when it lands.
Usually, the game ball size only various by a very small amount. For example; a one inch ball is used instead of a normal one and one sixteenth inch sized ball. This is done to increase the speed of the ball.


NOTE: We often find the standard size and finish game ball inside a game designed for a different sized ball. The game operator either didn't know or didn't what to spend anything but the bare minimum to get the game operational.

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

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  PINBALL GAME BALL DIFFERENCES 

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 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 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 side of the ball. The ball is then mounted 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. Newton balls don't normally have any ball specs and are probably made out of the cheapest ball someone could find to make 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 the Newton ball becomes loose. While they are more expensive to buy then normal game balls, Newton balls should be replaced almost as often as the game ball.

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

NOTE: Some refurbishment / repair shops will replace the game ball with the cheapest standard non-polished ball they can find or not even bother to change a rusty game ball before shipping the game.
This is why we spent so much time researching and finding a ball supplier with very high specs for our Laser game ball

A rusty game ball is just about the worst punishment you can do to your playfield, besides letting water get on it.

In general:
1) Rusty or dented balls cause the majority of playfield artwork destruction.

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

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

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 24. How are fuses rated? 

Caution: It is both a danger and a fire hazard to over fuse a circuit. 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.

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 at the better.
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).

Fuses 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.

On a Lighter Note: If you would like to totally baffle the coin-op repairman,
tell him (after he replaces a fuse and it doesn't repair the game);
"I know what the problem is. You put that fuse in backwards."
This will cause him to question his work for several minutes and you get to laugh at him when he/she finally figures it out.

Warning: This assumes the repairman will not charge more for the game repair because of this harmless joke. Pinball Medic will charge more when the customer "helps" with a repair.
Resistors don't have a polarity either, but most competent repair people put them in with the multiplier band on the right end of the resistor to make it easier to read the resistor's value. Resistors can also be used as a polarity joke but usually repair people get a clue faster with this part.

Standard arcade game sized (1.25 inch) glass body fuse.

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 FUSE SPECIFICATIONS    Return to Tip Index

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.

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).

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 and 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 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.

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.

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).

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.

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 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.

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 CABINET STYLES AND VALUES    Return to Tip Index

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.
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. Also, 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.

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

Dot Matrix Displays are usually used only on late model pinball games and some new amusement games (late model=1990 and newer pinball).

Dot Matrix Displays 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. A LED DMD will cost much more then a regular DMD display tube and driver board.

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 DMD SIZES AND SPECIFICATIONS 

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.

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

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).

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 27. Are there different Flipper bushings and what can worn out bushings do to the playfield? 

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  FLIPPER BUSHING TYPES DEMISTIFYIED AND THE DAMGE THEY CAN CAUSE 
Important Note on Flipper Bushings:
Worn out or 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.

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. Always Check your flipper to playfield gap before playing a game.

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.

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.

NOTE: The following games have not been completely verified to use the 03-6014 or A-2408 bushing.
Compare your old flipper bushing length to the new bushing before installing.

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, 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

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 28. New reproduction versus old original backglass/scoreboard glass 

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  DIFFERENCES BETWEEN THE ORIGINAL AND A REPRODUCTION BACKGLASS 

Using a new backglass versus an original is mostly at 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 and tends to look like it "belongs" on the game because 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 not be a problem with a new reproduction backglass glass.

Physical Glass differences:
A new glass may not totally match the original in color, be too shinny or have artwork design errors.
This "error" can be caused by the scanning method the manufacture used or the condition of the original glass. Most master copies are done by hand and then a silkscreen 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 then printed digitally (or at least the silk screen master is 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 copping process and some scoreboard glass reproduction manufacturers will intentionally make the image slightly different so they can tell an original from their copy.

Game Pricing Note: "Pinheads" can usually tell the difference between an original and a reproduction glass and therefore 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.

New glasses use newly formulated inks that might not completely match in color or the ink or reproduction process can be too good in quality to appear on an old game. Game buyers know that red, pink (pink used as a flesh color) and other hues classically peel away from the backglass of certain years of games because the inks used back then were not formulated correctly for longevity. They will peel with age.
New inks can last a lot longer then the originals. Ink flaking should no longer be an issue with a new backglass, although any ink will flake off glass if it is subjected to extremes in temperature variation. Glass expanses and contracts at a different rate then ink.  A silk screened backglass (and the game) should be kept in a temperature controlled area and should be shipped separately from the game to better protect the artwork from large game parts and vibrations.

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 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.
Photo shows a transformer with soldered on lugs for voltage adjustment or High Tapping

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  EFFECTS OF NORMAL HIGH TAPPING AND ABNORMAL VOLTAGE ADJUSTMENTS 

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 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. 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.

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

A) 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 up coil part numbers is the preferred way.

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 multiball 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 spec ed 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) The reason is because we can! High tapping is a very cheap and unskilled way to temporally "repair" a game without having to troubleshoot or replace any bad parts in the game. This allows for a fast turnaround for game sales people and because the damage can take awhile to occur, a field service call can be done after the warranty has expired providing illegitimate repair shops an extra source of income. High Tapping is also permanent unless the 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. Pinball Medic has often refused to service or purchase games that have had every board or coil fried because of abnormal high tapping. This is a common occurrence.

Modern pinball games (90's and newer) are somewhat "safer" to high tap then a middle aged game (70-80's) game because of improvements in voltage regulators and power supply designs. Electromechanical (EM) games can usually handle an abnormal high tapping because unlike solid state games, usually only the relay and solenoid coil supply voltage is 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 an low or high line voltage and not to improve the playability of a game.

Remember - Repairing a game is always better then a abnormal hack high tapping.

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

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  CAUSES AND REMEDIES FOR WEAK OR NON-OPERATIONAL PINBALL GAME FLIPPERS 

Flippers are some of the hardest and longest activated mechanisms on a pinball game. They have to be both powerful when moving the flipper bat and strong enough to hold a pinball game ball(s) when fully upright without burning up the flipper coil. Their coils can be complex and use two coils of wire on one solenoid body or one coil using very complex driver and trigger board electronics. They unfortunately are not an assembly that gets much 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 is often blamed for the decline of the pinball game in Coin-Op Arcades. Williams himself 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 that the game was not playable. 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 with very high point scoring instead of playability/fun to play orientated
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.

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 required to rebuild two flipper units. That right, 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.

Old to middle aged 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 a mostly burned out coil or bent flipper shaft. They need to be cleaned and re-adjusted periodically to maintain a good flipper strength. This 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 that are often pitted and burnt causing this switch to not make good contact and thus cause a weak flipper. Capacitors are often attached across or in parallel with the EOS switch to dampen the "coil kick back" inrush current that often occurs every time the EOS switch opens. EOS switches short out the large number of 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 turns to the total number of 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 old or new EOS switch needs to be adjusted so that 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 (to wide of a contact gap) the flipper will never reach its full strength before going into "holding" mode and will again appear weak. if there is not enough of a gap then the coil could eventually burn itself out.

The solenoid plunger and the flipper linkage claw are also problematic parts on a flipper. 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 and 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.

 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 bracket or bad mounting bracket holes in the playfield wood are major reasons for having to replace the whole flipper unit. What is 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 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/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 tries to either rebuild or replace 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.

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

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 site.
The home version type of game is different then a console video game that connects to an in the home Television and 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 a coin door and are built with half the normal pinball cabinet depth.

Realizing a few adventurous people may want to try and repair their game (power supply board can be repaired) and because Pinball Medic has no intension of ever repairing one of these types of games (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.

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  'FOR HOME USE ONLY' PINBALL GAME REPAIR 

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 full sized pinball games for home use. Also, 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/version 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. Even if a repair shop had the image for this ROM it would becost prohibitive to buy the special chip programmer to burn the software into the MPU chip to repair a few home version games. Also, this special MPU chip is no longer manufactured. Unavailable spare parts for these games makes them nonrepairable 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 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