I am working on a Bally Future Spa and magically the game stopped booting up. I will get two blinks then nothing. I tested all voltages from the transformer to the rectifier board to the driver board to the MPU. All voltages seem within range.

If I unplug J2 on the MPU the board will go through all blinks at startup and will start a game, but only the flippers will work. If I ground TP7 on the MPU board (while trying to test the voltage, the game will go through the blinks and start up. However, when you play a game, the features are mixed (left kickout lane will trigger pop bumper). Once the game is up, I get the correct voltage at TP7. On the times it doesn't immediately restart when grounded, I have less voltage at TP7.

I repinned the ground and voltage sections on J4 female plug, refreshed the solder on the board at pins 18 and 19 and did a ground wire mod suggested on another site to strengthen the ground connection.

The board doesn't have any corrosion. The battery was replaced with a memory capacitor.

I replaced the 5101 at U8.

since the connector at J2 seems to be related, I was going to repin the female connector there.

I have swapped in a working rectifier, then a working driver board, then a working alltec universal MPU all with the same results.

Does anyone have any suggestions?

I guess after thinking about it, I can't be grounding it when I am using the multimeter. Perhaps there is a charge built up that pushes the voltage over the edge. It is at 1.94 when it gets two blinks. When I disconnect J2, I get 2.84 which is much closer to the 3vdc the schematic says should be there.

Any suggestions?

That was my next step. I repinned the female J2 plug tonight with no luck. I get the same result with my alltek board, so I am guessing it is something in the wiring.

do you mean replace u10 and u12 or remove one and put it in place of the other? Why would I do that?

thanks,

figured it out. You were right. It was a short. the roll over switch on the left side was connected to the GI lights under the sling. Once I bent those back into place, everything is fine.

Thanks for the help.