Here goes...I have GI lighting and that is it. This happened after intermittent booting issues and resetting issues for several days. I have replaced both the MPU with a new board from Schwemmer and the Driver Board with new board Boston Pinball. I have done the ground mods at the transformer and show 5V flowing onto both the MPU and LDU. Displays are dead, Switched Lamps are dead, Sound is dead. GI lighting only. Help.

I don't know as I am at the end of my pinball knowledge base. How would I go about checking that?

Every so often you can turn the game off and on and then the GI lighting does not work but all Switched Lighting is full on and the solenoids/flippers all have power to them yet you are not in game mode and the displays are still dead.

I have a 5V power supply coming to swap out the one a have.

Thanks guys. It was indeed the 5V power supply. Picked up a new one and all is well. It was reading around 2.5V at the MPU. So the Swemmer MPU board would light as if all was well when it wasn't.

BTW at least for my Bounty Hunter the new power supply board was built where you have to install it upside down for your cables to reach and also rotate your connectors 180 degrees to match the supply pins. As a rookie, had I installed as "plug and play" I probably would have fried the board.