Stern Magic problems

[tonystein23]

I have a Stern Magic machine and it played fine until this week. Now when I start a new game, lights that shouldn't be on are on. Sometimes when the ball drains, the score just keeps counting up. And sometimes when the game should be over, it keeps giving me more chances. These different things seem to happen at different times when playing. Any ideas?

 

[Lindsey]

Sounds like a switch matrix problem to me though it could be an MPU problem manifesting itself as what looks like switch related problems. Or something else entirely.

There are a bunch of preventative maintenance items that these games require if they have not been done already. You can read about them and much more here:
http://www.pinrepair.com/bally/index.htm

I would start with the switch test and see if there are switches that are intermittently being seen as closed when they shouldn't be. If this is happening I would pull the connector going out to the playfield switch matrix (MPU connector J2). And put the game into switch test again. If the problems are gone you've got a problem with the switch matrix on the playfield. It might be as simple as adjusting some switches. If there are still switch closures being seen (that are playfield switches) with that connector removed then you've got an MPU problem.

If you find that it's an MPU problem I would start by re-seating the socketed chip. If that fixes it you've got socket problems at a minimum. If not you'll have to dig deeper into the MPU.

Of course, it could also be none of that but you have to start somewhere

 

[tonystein23]

thanks for your advise. Ill start checking!