Ok so this is my game but it’s at a friends house right now and it has a recurring issue. It’s Eight Ball Champ. The game will suddenly start scoring 1,000 points and just keep going by itself. I personally never saw it happen but my friend has 4 times. He called me the first time and I had him go into stuck switch test and the game told him 4 switches were stuck on; the 2 in lanes, right out lane and switch 16 which in the book is ‘not used’. All these are on the same row. I went to his house and examined all the switches on the row and they are fine. I couldn’t get the problem to occur while I was there. But it has returned since I looked at it.
My Question
Could this be the switch PIA on the MPU? Or do you have an idea for what it could be?

If it was a capacitor on one of the switches it would only lock on that one switch not 4 switches. If a diode on the switch was bad it would only activate other switches while one of the switches on that row with a bad diode was activated and not while they were all open.

#2 3 years ago

MSK

mskoenen

Slap Save Podcast

11y 63,550 369 32

You could determine if the issue is on the board or the playfield by disconnecting the switch column and row connectors and following this procedure. The guide is for a System 11, but the principle is the same:

https://www.pinwiki.com/wiki/index.php?title=Williams_System_9_-_11#Switch_Matrix_Row_and_Column_Testing

I've never worked on one of the 6803's, but from what I'm reading a bad cap(s) can cause some weird issues with the switch matrix:

https://pinside.com/pinball/forum/topic/bally-6803-switch-capacitors
https://pinside.com/pinball/forum/topic/bally-special-force-6803-1986-switch-woes
https://pinside.com/pinball/forum/topic/switch-matrix-issue-one-switch-triggers-another-bally-6803
https://pinside.com/pinball/forum/topic/bally-6803-self-test
https://pinside.com/pinball/forum/topic/help-game-tilting-bally-beat-the-clock

From the manual ( https://www.ipdb.org/files/761/Bally_1985_Eight_Ball_Champ_Manual.pdf ) here are the switches with caps:

E, I, G, H, T, all three rollovers, and the two bumpers. It doesn't show it in the schematics, but a lot of these have caps on the tilt bob, too.

Also, that keypad shares switches with the playfield, too. And apparently bad switches on the keypad can cause issues with playfield switches.

#3 3 years ago

AMS

barakandl

nvram.weebly.com

12y 132K 10,413

Usually failed capacitor wired across the playfield switch.

Try snipping one leg of the capacitor attached to that switch loose and see if the problem goes away. If it does that cap was bad.

0.047uF, cap code 473.

#4 3 years ago

???

Fordiesel69

Pinside member

Unknown

8y 45,400 363 26

Cut "ALL" switch capacitors. Then order replacements. Problem will be solved.

If for some odd reason that does not fix it, inpsect the star rollovers, mine broke and jammed sideways. Also the remote can be temporarily unplugged just do not loose it.

#5 3 years ago

CMS

Xenon75

Pinside member

11y 86,800 1,968

In addition to the switch caps, check the little key pad. that also can cause stuck switch issues as it sits in the switch matrix.

2 months later

#6 3 years ago

EJN

newbieinKC

Inactive member

Kansas City, MO

5y 31,300 228 1

Did the caps prove to be the problem? Mine had the same problem that went away when I replaced the caps. Just removing the caps made my EBC skip counting fast rolls but prevented the multiplier from going through the roof, usually after a good warm up.

1 week later

#7 3 years ago

ERK

ekthoren

District 82 Pinball

De Pere, WI

10y 84,850 478 131

The problem is fixed but I don't know what caused it. I did go through and replace a ton of stuff on the boards, caps, connectors, straitened out the wire harness, replaced some caps on the switches, etc. I did all this after I took the game back from my friend and put it back at my place. I couldn't get the problem to start again. So its been over 2 months and a couple hundred plays. It's fixed.

#8 3 years ago

EJN

newbieinKC

Inactive member

Kansas City, MO

5y 31,300 228 1

My wager is the caps on the switches. Common problem that manifests itself in several different ways.

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