It’s time to bring my old gal Eight Ball back to full life. Background: I bought this back in 1987 and did the repairs needed – a bunch of blown transistors and such (that’s what happens when someone puts the kickback diodes in backwards). It was then in great playing condition and I played it A LOT.

Now to today. We have some issues…..
- MPU board has to be pushed on to get it to creak to get it to boot up (actually it’s been this way since day one). I know – crummy sockets, maybe more.
- MPU battery is long dead, but no corrosion.
- Cabinet knocker driver is out. Happened when lightning struck just outside the house.
- There MAY be a couple light drivers out. Or maybe bad bulb sockets.
- Only a couple displays have all digits working.
- And the big one. Play for a bit and all of a sudden all the solenoids and displays quit. They just go out. It could be almost immediately, or it could be a while.

So I’d like some opinions and help. What I’ve done so far:
- Changed the transformer from 115VAC to 120VAC. My house line voltage is always at 124 VAC or higher. So why not change it?
- Checked all the voltages on the A2 Power Transformer board. All ok.
- Checked the TP voltages on the A3 Voltage Regulator / Solenoid Driver board. The TP2 Is at 230, but so is TP4. So the 190V regulator is out? But it’s the same when the game is running or when it quits.

Suggestions on where to go and what to replace? She’s been good to me and I have no problem putting money in. I’m an EE, so I understand electronics and can solder pretty well, but I don’t have a semi-professional station, but no sucker. I have all the schematics and manuals.
- Replace the Voltage Regulator / Solenoid Driver board?? If so, which one?
- Get a new MPU board?? Which one?
- Displays – are they worth trying to fix? I think I read somewhere long ago the problem is many times undersized (Watt wize) resistors. Or should I just replace them all with the new ones? I’ve seen at least three brands.
- What the heck is causing this mysterious shutdown?

And two good stories…..
I bought the machine in 1987 ($100) from Twin Galaxies in Ottumwa, Iowa – the proclaimed Video Game Capital of the World in the 80’s. Now home to the International Video Game Hall of Fame.
And lastly – my wife and I were in Budapest this year and she pulled off a surprise – rode the tram across town to go to the Budapest Pinball Museum for us to play for a few hours. Can’t beat that (or her)! I found Simpson’s Pinball Party – I actually liked it a lot (comments?).

After discovering pinball at age 10, this is my first post here. Thanks for any help.
Jon in MN

Thanks zacaj. So first I did make one decision - I took a careful look at the displays and the bad ones are really bad. Fixable probably, but a lot of work. So I ordered up a set of Wolffpac displays to build. That will be much nicer and less soldering work than working over the old ones. And I can now ignore any 190V problems (right?).

When the machine "quits," it's almost like a tilt, but not quite. All the solenoid items stop, any switched lights go off, the displays go off. But sometimes the flippers stay on. So I can agree that the MPU board might be at fault. That, along with the socket situation gives me the idea to just get a new Alltek MPU board.

Latest status….. I replaced all the displays with LEDs from David Wolff at Wolffpac. They are fabulous. They match the original color exactly. These come as a kit at a reasonable price. Solder the parts and you are done. I pulled the HV fuse on the machine – no need for that anymore.

The MPU board was causing the shutdown problem (thanks for the pointer). Reseating all the chips in sockets fixed it. But I put in an Alltek MPU board anyway. I didn’t feel like dealing with all new sockets. I hate desoldering without a professional station.

So a couple of new items…….
Bulb sockets are causing me frustration. Some will need to be replaced. I THINK I found some correct part numbers:
E-120-176 Staple down
E-120-127 Feature lamps
E-120-81 General lighting
E-120-162 Coin door
Are these correct? Is there a better list with quantities and locations? Where are some better places to buy?

The 8-ball target switch is not consistent. If you just bump it, it will trigger. But if you have a full on rocket from the left flipper, it will slam the target and not trigger. I looked at gap and it seems OK. I used a business card between the contacts to clean. No change. Is this common or should I buy a new switch?

So speaking of switches. Is there a switch part number list somewhere? I have the Game Operation Manual and the Electronic Repair Manual and neither has switch numbers.

Yup, it was missing the cap. Thanks! I found one laying around in my electronics pile and soldered it in. I think it's better.

Now on to the sockets. Are those numbers correct?