Quoted from Lovef2k:
I always start at the power supply. The rectifier board at the bottom of the main cabinet. Known as the -54. These boards tend to have burnt traces on the bottom so visually inspect it. Replace if you see dark spots. Marco sells a replacement.
You will need a good quality VOM meter. I suggest the Fluke 117 if you need to buy one. Unplug J1 thru 4 on the -54 and check the test points. This will be a no load test. If you don't know the values you can find them on pinwiki.com in the Bally/Stern section. There's a ton of helpful info about all of the boards in the game.
I believe all of the voltages are DC except the GI voltage which is AC so adjust meter accordingly. If you get a reading that is way off or zero. Unplug game and check the fuse by ohming it out, sometimes a fuse may look good but still be bad.
Also make sure the fuses are the correct type and amperage value.
If everything checks out good with power supply, reconnect connectors there and move on to the solenoid driver. Verify voltages at test points. Again pinwiki.com has all the info you need. If solenoid driver is good move on the mpu and do the same. The power supply and solenoid driver board have a high volt section so be very careful not to touch with bare hands or short anything with your meter probes.
Disconnect the sound board power up game paying close attention to the led on mpu board. There should be a flicker first and then 7 flashes if mpu is working correctly. If not count the flashes and report back here.
Visually inspecting the bottom of the power board at the bottom of the cabinet there is a white contact fluid/paste with big blocks. Haven’t seen that before.
All fuses are correct. Board looks ok, no burned connectors . Some random jumper wires soldered on that might be old fixes?
Fuse holders look ok. Board looks pretty clean, no brown or burned out traces. Everything appears to be ok so I proceed to the solenoid driver board.
On inspection I have a burned connection and wire on the 9th pin slot labeled Transformer Ground. I re pinned it but am not happy about the molex connector having a black spot. All wires seem to be fine.
After checking everything you suggested and installing the new board I fired it up. I have all sound and functions! I ran 1 ball through it and it looks good so far. I then turned off the machine and unplugged it.
On the solenoid diagnostic LED’s the last light labeled Q19 D22 remains lit.
The Cyclone LED’s are rotating correctly and when the ball hit targets the diagnostic LED’s flashed red accordingly for a fraction of a second. What’s next? Also, thank you all so much for the generous help!
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