Repair & Maintenance Log
08/14/08: Ordered a reproduction playfield plastics set from Classic Playfield Reproductions. I thought I might own this game someday.
10/08/11: Acquired game.
10/09/11: Replaced power cord.
10/22/11: Installed new reproduction backglass from Classic Playfield Reproductions. Vibrant colors, no flakes or cracks and no crappy "CREDIT" decal in the credit window. This looks great!
Reproduction CPR backglass.
10/22/11: The MPU board was equipped with an evil NiCad battery. I doubt it was original. It still worked and the board was damage-free. Nevertheless, the battery had to go. Instead of implementing a remote battery circuit, I replaced the old RAM chip (which can be unreliable anyway) with a modern non-volatile memory chip from Tom Callahan at pin-logic.com. The chip comes with a small circuit board such that the wider new chip can piggyback on the old narrower socket. Assuming the old socket is healthy, this is a plug and play modification. I folded down the TP6 wire hoop so as to not interfere with the new larger chip.
Original RAM chip and NiCad battery.
New non-volatile memory chip and no battery.
03/18/12: New playfield glass.
03/24/12: Installed standard-keyed (751) lock on coin door.
11/21/13: Restored coin door. I like coining my games and I hate homebrew credit button hacks. The coin door on this game looked good from the outside, but had been virtually gutted on the inside. I looked around eBay and found a bashed in coin door that had just about all the hardware I was missing including an unmolested wiring harness. I stripped both coin doors, cleaned all the parts and reassembled a complete door. The only other parts I added were three new lamp sockets, three coin mechs and a new SBA door decal. I pulled out the credit button hack, glued in a wood plug and touched it up as best I could with colored markers.
Here's how my coin door looked when I bought the game. Not much left.
My bashed in eBay parts door had just about all the hardware I was missing.
The parts door had a complete wiring harness.
Everything back together.
Hack credit button before (left) and after.
Finished up with a new SBA decal.
11/21/13: Repaired voltage regulator board. The game had some random reset issues and there were some connector hacks at J3. I replaced the big filter caps C23 and C26. I made the ground modifications recommended at www.pinwiki.com. I replaced all the header pins at J1-J5 and I re-pinned all the connectors. I set the high voltage output down to 170 volts to reduce stress on the displays.
Voltage regulator board before repairs.
Voltage regulator board after repairs.
11/22/13: Repaired rectifier board. This game came with an aftermarket rectifier board that appeared to work just fine. But it wasn't mounted correctly because of a conflict with the grill around the transformer. I cut a notch in the grill to properly accommodate the board and I replaced all the nylon pcb standoffs. J3 pin 8 was toasty and hacked so I replaced the whole connector. Pin 8 (orange wire) is the unregulated 11.9 volts. The other end of this circuit at J3 pin 12 on the regulator board was also toast (see above).
Rectifier board before repairs.
Rectifier board after repairs.
11/13 - 12/13: Shopped playfield. There weren't any major problems with the playfield. Mostly it was just moderately dirty and needed some TLC. I cleaned and waxed the playfield. I replaced all the playfield rubber. I did a lot of other little things as outlined in the paragraphs below.
I finally bought a parts tumbler (Cabela's Model 400) which came in handy for cleaning all the metal playfield parts. I still haven't found the courage to strip an entire playfield all at once. I started at the top and just worked on one small area at a time.
The game has a bunch of white nylon spacers that support plastics from underneath. Some were missing, but I had spares. Someone got seriously carried away with the liquid wax. It was everywhere, even under the playfield.
Here's an example of the playfield's condition. Not too bad.
Same view as above after some cleaning and reassembly.
The biggest visual detraction was the seven burnt and yellowed bumpers. I replaced all the plastic bumper components with new parts. I also added new lamp sockets, coil sleeves and rubber. Tip: put the new rubber rings on the passive bumper bodies before assembling the bumpers. I don't think any of the bumpers had ever been serviced except for the left thumper bumper which had a new coil. It also had a oddball plunger and a missing coil stop. No coil stop means the plunger was bashing on the spring and fiber yoke. But there appeared to be no damage. The coil stop is an integral part of the bumper bracket and I had no spares. So I grabbed an old flipper plunger and cut a "puck" to fill the space of the missing stop. This was just a temporary fix. I wanted the bumper back together so I could test the rest of the playfield.
Update: I replaced the bracket and plunger with new parts. I couldn't find an original looking bracket with that extra reinforcement layer at the elbow. Otherwise my replacement is dimensionally the same. Another Update: I think I've decided that these bayonet bumper sockets suck. Even if they're new they suck. Next time I do a bumper rebuild I'm switching to wedge sockets.
Here's the oddball plunger and my homemade "puck" to fill the space of the missing coil stop.
New bracket (installed) compared to the original.
A before shot of the seven burnt and yellowed bumpers.
New bumper parts. New plastics. Cleaned and waxed playfield.
I don't have the ambition to touchup a playfield so I'm not willing to risk removing the playfield Mylar. Fortunately the Mylar is pretty solid, which is one of the reasons I bought this game to begin with. However, there were a few places were the edges were lifting. Lifting edges collect dirt and look nasty. I used an X-Acto knife to carefully trim away some of the lifted edges. The trick is to cut the Mylar without scratching the playfield. With a fresh blade it doesn't take much pressure.
Before trimming the lifted Mylar edge and cleaning the playfield.
After trimming and some playfield cleanup.
The post to the right of the "N" target had obviously been left loose for a long time and much of the wood under the post had been bashed away. I filled in the missing wood with a two-part stick epoxy. I used a wet piece of small PCV pipe to roll the epoxy flat and I used Novus to cleanup any stray residue before it cured. I didn't bother trying to touch it up because most of the repair is hid by the post.
Playfield damage under the post by the "N" target.
Damage filled with a two-part stick epoxy.
Post back in place.
The plastic over the center hoop was supported by six of the shorter red posts. The underside of the plastic was wearing on the metal ball guide. I replaced the shorter posts with six of the taller red posts as shown. Note that the two posts by the "N" target are still of the short variety. The plastic now clears the ball guide but has a slight conflict with the center bumper cap. Nevertheless, having the bumper cap press down a little bit on the plastic is better than having the ball guide wear through the graphics on the underside of the plastic.
I added six of the taller red posts around the center hoop.
Here's the new plastic mounted on the taller posts. The bumper cap causes some slight warping, but it's barely perceivable.
I don't have a buffing wheel. To polish screw heads I chuck the screw in my drill press (just hand tight) and run the head on a rag with some Novus. It only takes a few seconds per screw. Yeah, it would be easier to use the parts tumbler, but the drill press method works well when I only have a few screws and I want immediate results.
A polished screw head (left) compared to an unpolished head (right).
I like to periodically test the playfield as I work. I noticed that both spinners had died. The problem was a broken input wire (row I0) at the disappearing kicker switch. I stripped and twisted the two wires then soldered them back to the top switch terminal.
A broken daisy-chained input wire at the disappearing kicker switch killed both spinners.
The upper post by the left slingshot had been blown out. Someone fixed it by retrofitting the post with a machine stud and T-nut. Good idea except the post was in the wrong place. I trimmed away some bad Mylar, tapped out the T-nut and filled in the big hole with a two-part stick epoxy. Then I re-drilled the correct hole, reset the T-nut and reinstalled the post.
A big hole in the wrong place and some messed up Mylar.
Hole filled and re-drilled in the correct location.
The post back where I want it.
Good thing I got some extra bumper brackets because I found another broken bracket at the left slingshot. Maybe that extra reinforcement layer isn't so important after all. The bracket was cracked right at the elbow. Or maybe that extra layer was intended to be more of a failsafe than a reinforcement. Even though the end of the bracket was broke off and just floating there, the extra layer prevented the assembly from falling apart so the game still worked.
Another busted bracket at the left slingshot.
Bracket replacement.
I disassembled and cleaned the disappearing kicker components. I don't know that this was really necessary. The unit looks pretty robust and probably doesn't care if it's dirty. If the switch and coils are unsoldered the whole unit can be removed with just four screws. But I decided to leave the unit in the game. Instead I removed the individual moving parts. The biggest challenge was being careful not to launch all the retaining clips across the room. I cleaned everything and polished the kicker arm since that's the only visible part. Then I put it all back together again. I don't like that there's a stray winding outside the wrapper of the kicker coil. But I didn't have a spare so I wrapped it in tape and reused it. I also rotated the coil 90 degrees so the terminals are pointed away from the assembly. The coils are easy to remove so I'll just get a spare with my next parts order. I'll probably also order some spare Nyliner bearings. There are three Nyliner Bearings in the kicker assembly that ride on the two guide rods. Looks like they have about a ¼" inner diameter.
The disappearing kicker before disassembly.
Here are some of the parts I pulled from the disappearing kicker unit. Note that the spring goes with the right guide rod, not the left. Note the three Nyliner bearings that ride on the two guide rods. Note the nylon bushing on the end of the kicker plunger.
Everything back together. Note that I rotated the kicker coil so the terminals are away from the assembly. I also taped and zip tied the coil to secure the loose winding.
Eventually I discovered that the ball was not reliably centering itself in front of the disappearing kicker arm. If the ball isn't centered, it's kicked into the tip of the flipper instead of straight up the playfield. The problem seemed to be that the rollover wire wasn't properly centered in the kicker arm's playfield slot. At first I thought I might have to disassemble the whole disappearing kicker unit (again). But by removing just one guide rod I had enough clearance to jiggle out the rollover wire assemble. Once out I could adjust the wire. It took a few tried to get it right.
The wire rollover assemble out of the game.
The wire rollover properly centered in the playfield slot.
Both flipper mechanisms needed to be rebuilt. The left flipper had a broken coil sleeve. The right flipper had a broken bat, an oddball pawl assembly and a messed up EOS switch (thanks to the incorrect pawl). I replaced all the parts including both bats.
Left and right flipper mechanisms before rebuilding.
Right flipper mech rebuilt.
No surprises under the apron. I simply pulled off the parts, cleaned everything and put it back together.
Trough components cleaned up and ready for the apron to go back on.
The plastics on this game were a little warped and a little yellowed. But there were no cracks, chips or missing pieces. I probably would not have bothered replacing them except I already had a reproduction replacement set from Classic Playfield Reproductions. Before installing the plastics I added a Mylar undercoat. I tried this on my Space Station game. That was five years ago and it seems to have held up. Silverball Mania has a bunch of nylon spacers on the playfield that support the plastics. The screw heads can wear through the screening on the plastics which is what I was trying to prevent. CPR plastics have a protective paper on the underside that obviously has to be peeled off before applying Mylar. I taped the Mylar down on a glass table sticky-side-up. I placed the plastics on the Mylar then cut them out and trimmed them up with an X-Acto knife. I spent some time with each plastic using a fingernail to burnish the Mylar film. This is a good project to do in front of the TV. I did not Mylar the center hoop plastic because I didn't want to obscure its transparency. I finished up the installation with new nylon acorn nuts.
An example of one of the nylon spacers that supports a plastic.
And here's the corresponding wear mark on the old plastic.
New CPR plastics placed on a sheet of Mylar. Note that the plastics still have their protective top film. I peeled that off later.
Topside done!
In a game like this with so many stationary targets it's extra important to have all the controlled lamps working properly. It's the only way to know what's going on. I didn't find one burned out bulb under the playfield. All my problems could be attributed to faulty lamp sockets. I decided to just solder them all. First I added some solder between the mounting bracket and the socket body. Then I moved each control wire from the terminal directly to the spring thingie in the center.
I started by using a cutoff disk in a Dremal to grind away some metal at each point where I intended to solder. I tried a small wire wheel, but it didn't seem aggressive enough to get down to clean metal. Using a cutoff disk around wiring harnesses isn't a good idea either. It takes a lot of care and patience. I worked on just a few sockets at a time and took a lot of breaks. Next I added a dab of paste flux at each solder point. This is critical. Just a tiny dab makes all the difference. After soldering all the sockets, but before turning on the game again, I tested all the sockets for shorts. Actually I did this twice. The last thing I wanted to do is blow up lamp drivers.
A old lamp socket "soldered shut".
I only have two hands so I added some zip ties to my meter and hung from the nearest coil bracket.
Some sockets are hopelessly cantankerous. Maybe it's easier to just replace the damn things. My next parts order will include a bulk quantity of new lamp sockets.
New lamp socket.
Replaced five missing switch capacitors. It pretty easy to see where capacitors have been cut away, but the proper locations are also noted on the switch matrix schematic.
New switch capacitor.
12/20/13: Repaired sound board (maybe). The sound board would operate in one of three random conditions:
1) Works just fine.
2) Doesn't work at all.
3) Works, but produces a completely different set of sounds.
I have no idea what would cause condition number three and I couldn't find much trouble shooting information about this generation of sound board (AS-2518-51). I decided to start with some general housekeeping. I replaced all five electrolytic capacitors. I replaced the volume pot. I replaced all header pins. I re-pinned connector J2. Maybe I should have also re-pinned connector J1, but it's one of those daisy-chained IDCs that I really didn't want to get involved with.
My board had a 220uF cap at C8. The schematics call for a 470uF cap. Apparently this board was produced with both. A 220uF cap allows an output range down to about 90Hz. A 470uF cap allows an output range down to about 42Hz. The cap kit I bought came with a 470uF cap for C8 so that's what I used.
I decided to jump the negative lead of C15 to the board's ground plane. I applied the same mod philosophy that's applied to the big filter caps on the regulator board. Why have the negative lead of C15 loop through a bunch of connectors to the rectifier board and back again? I simply bent the negative lead of my new C15 cap and soldered it to ground pin J1-14.
Did any of this work? So far so good.
Sound board before repairs.
The negative lead of C15 soldered to ground pin J1-14.
Sound board after repairs.
12/22/13: Added remote volume control. I wanted to be able to fine tune the game's volume without always pulling the backglass. I looked to my Xenon for inspiration. Xenon has a remote volume control inside the coin door comprising a 100 ohm potentiometer. Xenon uses a different sound board, but it's essentially the same output amplifier circuit. I figured what works for Xenon will work for Silverball Mania, so I bought a replacement 100 ohm potentiometer.
I mounted my remote volume control behind the cash box using a hardware store bracket. It's an easy reach from the coin door. I duplicated the circuit from Xenon. The negative speaker wire is extended to the low side of the potentiometer. The positive speaker wire is removed and extended to the high side of the potentiometer. A third wire is run from the wiper back to the vacated positive speaker terminal.
I set my remote volume control about halfway. Next I set the game volume from the sound board to about what I wanted. Then I readjusted the remote volume control to exactly what I wanted. Any further adjustments can be made right from the coin door.
Remote volume control.
View from the coin door.
10/10/14: Sold game.