Hi folks, I have a System 80B MPU that is giving me fits at the moment. Right now, there is no boot, no displays, couple inserts locked on, and GI lit up when I turn the power on. No solenoid thunking.

What I have done:
Verify good 5v on the MPU
Swapped MPU into a known good machine and had the same results, so I know it is the MPU.
Daughter board has been reflowed previously and pressing on it does nothing when trying to boot. Also pressed on it with reset board plugged in.
Reseated the ROM chips and also swapped in known good ROM chips and no change.
None of the 6532's seem to be getting hot, as well as the Z11-14 IC's

I have been google searching for past threads, and I am not seeing much beyond what I have already done. I have had some issues with 6532's before...can the failure of one of U1/U4/U5/U6 cause the machine to not boot at all?

Thanks,
Jody

I measured the voltage at the capacitor by A1-J1. I'll start with the U2/U3 continuity test and see if that shows any issues before go the Piggydeux route. Since that area has been heat cycled once before by someone else, I don't want to do it again and risk removing traces if I do not have to. I down a FR-300 and am comfortable doing good soldering work, I just don't want to start shotgunning good components.

Thanks Chris! I actually just ordered the Piggydeux with Marco's ROM this morning and will give that a shot. This is like the 3rd time I could have used one of those, so I finally decided to just get one and be done with it.

People love to rag about working on 80B's, but I would 100% rather work on an 80B MPU over a System 11 MPU. The traces are way more forgiving on the Gottliebs.