Maintenance and repair of modern pinballs

Contents




Cleaning and waxing

After you get your latest acquisition home, it must be put in the best possible shape. Every part does not have to be changed, and depending on games age that might even be hard. So let's concentrate on replacing or repairing the most worn parts.

First, the game should be cleaned thoroughly. This usually demands removing all parts from the playfield. Make notes or take some photos so you get it all back afterwards. After the playfield is stripped from parts, it is easy to clean. For the first time, use mixture of water and alcohol to get all grime off. On next cleanings, it is best to use more conventional stuff. When the playfield is clean, wax with a good quality Carnaubawax, or in case of a Diamondplate, clean with Novus #2, then finish off with Novus #1. Do not use petroleum distillate containing waxes on Diamondplate!

When cleaning, do not forget the playfield's underside. All ramps, tunnels etc gather surprisingly large amounts of flipper dust. They should be cleaned every now and then. At the same time, check that all screws are tight. Be careful not to crack any plastics, they get fragile after years. If a plastic breaks, you might try repairing by glueing a piece of plexiglass with epoxy to the break. You can first shape the plexi by heating it with a hot air gun and flexing carefully.



Lamps

All lamps must work. If the game has burned general illumination lights, it looks dark and not very appealing. And if the feature lights are out, the player does not know what to do. When you replace burnt lamps, clean the feature lamp insert plastics. Contact cleaner spray is good stuff here. A short squirt will get flipper dust out of the insert. Sometimes the inserts rise a bit from the playfield level. You can try carefully pushing them down with a rubber hammer and then supergluing from the underside.

Rubbers

Gameplay depends much of the rubbers. They are not expensive. Buy a complete set of rubbers for your game and replace them all at a same time. White rubbers are more bouncy, but some newer machine use black rubbers for good looks. Remember that UV light makes rubbers yellow, so it might be wise not to put fluorescent lights above your games. Do not keep your spare rubbers under fluorescent lights either! Very important is the shooter tip rubber. If it is missing, the shooter makes dents to balls, that then damage the playfield. If balls are dented, replace them immediately! Use 1-1/16" ball bearings. A little scratchy or dull balls can be polished.



Fixing up a game after Mr. Repairdude

Mr. Repairdude is a pinball mechanic. He leaves the games usually in a good condition. Sometimes not. Sometimes they are almost useless, but usually he gets any machine working so well that it accepts coins. Of course that is the most important thing for the operator. Mr. Repairdude has to work in bars, while friendly customer watch by and give him friendly advice. He must use those tools and spare parts he has with him. Because of this, all his repairs are not done in the best possible way. It is very different to fix a game at home, with no hurry, proper tools and spares and in good light. So try to understand Mr. Repairdude, he has done the best he can. However, it is wise to redo the quick fixes properly when there is a possibility. So does also Mr. Repairdude, when he gets the game to his workshop for a thorough overhaul.

Repairdude
Don't let this guy near your pinball!


Check all fuses and replace with correct sizes. Mr. Repairdude may have had only 20 A fuses with him, or maybe some other fault has caused the smaller fuses not to last. Too large fuse will generate more problems. Get yourself a good supply of fuses. If a correct sized fuse blows, there is a fault somewhere. Correct the fault, don't use a larger fuse! Maybe the repairdude has replaced a coil with one of similar size mechanically but not electrically. Check your game manual for info on fuses and coils. Check that all coil plungers move freely inside the coil. If not, try first cleaning the plunger and coil sleeve. If that doesn't help, replace the sleeve. Check that the coil stops are not deformed. Also remember to check for a protection diode on coils, that should have one.

Sometimes the repairdude has bought a can of WD-40 or some other Really Good Stuff, and sprayed it everywhere in the machine. This makes practically everything to gum up and stick. You have to then take everything apart and clean. Big job from a small can! The solenoid plungers do not need any lubrication. All metal-plastic bearings are best left unlubricated. In a modern pinball there are few places that do need greasing. Slingshot lever hinge, and the ball feeder lever hinge. Maybe the shooter rod. Not much else. If some place is sticking, do not try to correct with oiling, but cleaning.

As mechanical parts wear, also the screw get loose in the constant vibration. Sometimes Mr. Repairdude has replaced the fallen screw with a little bigger. Hopefully his screws do not come thru the playfield. If a screw doesn't hold anymore on playfield underside, drill the hole a bit larger and insert a piece of wooden stick to the hole. To that, drill a new hole for the screw.

Also on the playfield there may be creations of Mr. Repairdude. A ramp has cracked or some wire gate broken. The dude has fixed them with duct tape and bubble gum. Get some piano wire, make new wire gates from it. Fix the ramps by epoxying a piece of plexiglass to the damaged part. If available, order new or used but intact spares!

Flipper fixing

The most important parts in a pinball are the flippers. If they do not work well, even an otherwise nice game will not interest players much. Fixing the flippers is not difficult.

All flippers operate in basically the same way. When the player pushes the flipper button, a strong current goes through a heavy coil, pulling the flipper plunger quickly in. After that, a lighter coil is switched in, for not to overheat the coils if the button is kept pressed for long time.

Flippers have a two part coil. The two parts, power and holding windings are wired in series, and the holding winding is shorted by the EOS switch. When the flipper operates, current goes thru the power winding only, and then when it has pulled in, the EOS switch opens and current begins to go thru both windings and is reduced. IF the EOS switch is improperly adjusted and does not open, the coil quickly overheats and the plastic sleeve inside melts. If the EOS is always open, the flipper feels very weak.

Bally/Williams games from 1992 have a Fliptronic system, that has opto switches at the buttons and electronically controlled coils. If the EOS switch does not work, the electronics automatically turn off the power winding after a while to prevent heating. The coil does not get damaged. But it is important for the good flipper feel, that the switch does work properly. Note: on Fliptronic games the EOS switch closes when flipper operates, instead of opening like in the older games.

In older games the flipper button directly controls coil voltage. The contact points must be cleaned with a contact burnishing tool to get enough current for the coil. The same holds for the EOS switch points. Newer Fliptronic machines only need the flipper button optos cleaned with pressurized air occasionally.

Every once in a while, check the flipper plunger and coilstop. They are not expensive, but are very important parts. After time, both the plunger and the coilstop ends get deformed from constant banging onto each other. When changing the plunger, replace also the coil inner plastic sleeve. The coil itself needs no replacing unless it overheats. Do not use brass or aluminium sleeves. Modern Teflon sleeves cause much less friction.

Sometimes the plastic bushing going thru the playfield must be replaced, or at least cleaned. When cleaning the playfield, cleaner and wax go easily inside the bushing and eventually make the flipper shaft stick to it. When replacing flipper parts, check the vertical play on the shaft. Should be at least 0.8 mm. If it is too tight, the flipper sticks. Every once in a while turn the flipper rubber to a new position, or replace it.

When the EOS switch is properly adjusted, coil sleeve and playfield bushing clean and intact, and other parts have been checked, the flipper operates strongly and exactly. At home use it will last very long time.

Bumper fixing

Besides flippers, also bumpers are an important mechanism to move the ball. Sometimes they need a little maintenance too. The mechanism is simpler than in flippers. The ball pushes a plastic plate, that tilts a little. Attached to the plate is a stick, whose other end is at the bottom of a spoon like switch leaf, and when the stick moves the switch closes. A solenoid then pulls a cone shaped metal ring towards the ball, which then propels outward. Check that the coil sleeve and plunger are clean and in good shape. Clean or replace if needed. For the trigger switch to operate correctly, it is important that the moving stick is exactly in the middle of the spoon. Slight adjustment can be made by loosening the switch screws and moving it a bit.

The spoon must be clean. This is one of the places Mr. Repairdude may have used some grease in. That grease turns into bubble gum-like substance in years. Clean the spoon, and if you absolutely want, put a very little drop of silicone spray to the spoon. If you are unsure, do not lubricate.


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