Millipede issue-garbage screen

killerbooger

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When I boot the game up it looks like the picture attached. It is not the board. I checked the power supply it seems to be ok as well. Also swapped it, no change. Im a little stumped.
 

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did you swap boards? That is how you know its not the board?
You say you swapped it, but not sure if you swapped PCB or PS?
 
Turn the game off.

Flip the Self Test switch inside the coin door.

Turn the game back on.

Report / post pictures here of what you get.

Did you check the 5 VDC voltage to ground on the board (at the spots on the PCB)? The edge connector can corrode and tin corrodes slight resistive. You may be taking a voltage drop at the connector. TTL logic has to have pretty tight voltage on the 5 VDC rail or it gets all confused.
 
I tested the power supply and it was fine. Swapped it as well and still had this screen. I took the board out and put in a working game worked fine. I will
check that self test switch. I did test it but maybe it is bad. that would explain it. Whatever it is, it is localized on this cab. Is not the boards.
 
Make sure the game board is getting 10.3v from the brick. It comes into the game board via a dedicated wire. See the wiring diagram in the schematics. It is required for the power-on reset circuit.

It looks like there's no 10.3, and the CPU isn't running as a result.
 
Make sure the game board is getting 10.3v from the brick. It comes into the game board via a dedicated wire. See the wiring diagram in the schematics. It is required for the power-on reset circuit.

It looks like there's no 10.3, and the CPU isn't running as a result.
it's generating +5V or else there would be nothing on the screen, how could the 10.3V be missing?
 
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