I was running the machine up until a couple days ago, and shut it off later in the evening. When I tried to turn it on the next day, I just got a white screen and the lighted buttons on the control are staying on- The computer is not booting. I have confirmed there is 115V power at least getting to the computer power supply. There are LEDs on the main board indicating 12v is there, so I'm curious where I should start looking next.

I am trying to remember the common issues of days past- For starters I guess I will try changing the CMOS battery, and reseating everything.
If anyone has ideas on what I should check please let me know.

Update: changed CMOS battery, reseated boards, no change. I noticed there is a light for 5v status next to the 12v light. It is not illuminated, so I suspect a power supply failure on the 5v line. Going to check things with a meter to be sure, but if that's the case this should be an easyish fix.

Update #2: Power supply reads 2.5v on the 12v line, 1.2v on the 5v line while plugged into the board. When the power supply is disconnected, voltage reads about normal.

This means either the supply is dead and not maintaining voltage under load, or there is a short somewhere. About to unplug everything and add one board at a time to try to get a better picture. Meanwhile, I guess I should shop for a replacement power supply. It's not ATX, so will be hard to find unless I want to butcher cables and transplant a new supply.