Bally Solenoid Driver/Voltage Regulator Board Issue

[Lindsey]

Could it get to such a high temperature so fast...under a minute?

Easily. Use the old finger test

 

[dieseldogpi]

OK, got home today and booted the game with only J3 and J4. Same issue happened, attract mode for a bit, then off. Turned it off then back on I went to touch the transistor to see if it was hot, when i touched it, the game turned off again, and the transistor felt warm. Not being able to repeat the turning off by touching the transistor, I detached the board, removed both transistors and put heat sink silicon on them, resoldered, reflowed some solder points on the plugs and put the board back in. With only J3 plugged in...same result, boots everytime, then a couple of seocnds (30-40) off. So frustrating. So now I dont know if it is an MPU issue or what. I did bench test the MPU previously with a pc power supply, and the board booted every time. I need to walk away from it for now...as i dont want to smash it, I guess tomorrow I should be checking voltages for spikes and drops?

 

[Deadly]

http://users.esc.net.au/~boots/Pinball_Guides/Bally_77_85/index1.htm#reset

Also those pesky interlock switches are known to be problematic.
Keep going - you'll get there!

 

[Lindsey]

OK, got home today and booted the game with only J3 and J4. Same issue happened, attract mode for a bit, then off. Turned it off then back on I went to touch the transistor to see if it was hot, when i touched it, the game turned off again, and the transistor felt warm. Not being able to repeat the turning off by touching the transistor, I detached the board, removed both transistors and put heat sink silicon on them, resoldered, reflowed some solder points on the plugs and put the board back in.

What transistors are you talking about? The voltage regulator is the bottle cap looking thing on the huge heat sink. Make sure the screws are tight.

With only J3 plugged in...same result, boots everytime, then a couple of seocnds (30-40) off. So frustrating. So now I dont know if it is an MPU issue or what. I did bench test the MPU previously with a pc power supply, and the board booted every time. I need to walk away from it for now...as i dont want to smash it,

Seems unlikely to be an MPU problem.

I guess tomorrow I should be checking voltages for spikes and drops?

If you're going to follow my advice then yes. That's the first thing I suggested to do. Break down the problem systematically. That's the most direct approach. Starting with the voltages.