Quoted from BigAl56:Lets start over...This is a Bally Groundshaker right? Can you post some pictures of the MPU and rectifier board by the transformer?
I'm thinking burned connectors on the rectifier board and possible MPU battery damage. How many flashes on the mpu LED when the game boots? Should filcker then flash 7 times.
Ok, was finally able to see the machine again. MPU honestly doesn't seem to have batteries at all, I'd expect to see AA batteries? The LED on the MPU is indicating an error (not sure fully what) flashes a single time, with a short delay, then two more and then goes solid green. So three flashes? The power supply board however, there appears to be someone's previous repair job on it in the lower left, one of the mosfet appears replaced and the traces on the back near it must have been damaged and pulled up. They jumpered a wire across (possible ground) to have continuity going across. There's a resistor above this one that behind it on the PCB board is burnt/something had caught on fire at some point. But the resistor doesn't look burnt, and hard to determine if previous repair person may have replaced this resistor. The burn on the board originates from the mosfet, but the current one appears to be original to the rest.
I've brought the power board home to try to clean up this butcher repair job and test the resistor/mosfet. I checked all fuses and they check out, are passing current. After reseating these again after testing, there was one single light on the playfield showing lit, which it wasn't before, but still everything else on playfield dead/no power or life showing.
Tim