Quoted from wugly:had a corrosion problem on a harlem globetrotters. rebuilt the board using a corrosion repair kit and the game worked fine. decided to write new roms using 2732 with freeplay code, I changed the jumpers. I believe I got everything right. tried to boot the game and the game wouldn't start. game is at friends house and I think the led came on for a moment then went off. took board home and tried to get it to start at home on test bench using a test grade power supply not a pc power supply. If I take off the 12 volt power from tp2 then reattach I get the 6 blinks. seven if I put in the voltage for tp3. what could I have broken during this switch or are the proms causing me reset problems?
The bally MPU's power on reset was designed around how the voltages come up in a linear power supply. A PC power supply may not reset the board properly and leave you with a locked on LED.
If you get all the flashes by manually resetting then the MPU is probably OK unless there is some kind of reset problem beyond that you are using a PC power supply.
You can gently flex on the MPU and chips while you have it on the bench to see if it locks up. Otherwise check the voltages using the test points of the MPU while it is in the game. Taking the board out may have taken out a marginal connector.