If there is no display load on the power supply, the voltage will be higher. If your BH is wired for 110V and this is what your outlet should be, I'd try putting some of the displays (if known good) back on line and see if the voltage pulls back closer to the correct load voltages.

Steve (posting from the hospital)
System 80, not just a job, it's an adventure

Hi ForceFlow, glad to see you in this thread, hopefully Chris will hang in on this thread too. It's also good to see other System 80 guys helping on this thread as well wiredoug.

I just checked in to see what progress was made, I'm a little foggy from the Chemo treatment and I'm not near any of my schematics right now. So I'll ask a question about a common System 80 power supply issue that can shut down the displays without blowing the display fuse. Have all the header pins had the solder re-flowed at the A2 board? Making the power supply solid is the start of a healthy game.

It is common for solder cracks to form around any header pins in System 80 games. It might be where the display power has been lost at A2. While you have the A2 board separated from the heat sink you may want to replace R10 and CR7 with the correct parts as suggested in PinWiki if it hasn't been done yet.

This also happens at the pop bumper boards so keep that in mind for later.

As has been mentioned by wiredoug, another cause of display failure is the loss of the 5VAC to the displays, IIRC, there is also a connector involved in that line that will need to be looked at, I've seen it fail there in my BH.

You may also need to go back and check the displays themselves. One of them may have failed and shorted to ground taking all the displays down with it.

I'll check in later to see if the problem has been solved. Wow, lots of typing with numb fingers, I hope I didn't screw up too bad.

Steve (posting from the hospital)
System 80, not just a job, it's an adventure