EDIT -- RESOLUTION: Verified Rectifier Board Connector J3 Pin 8 was providing 11.9V, verified wire (when connected) at Pin 8 was showing the voltage too. Followed wire to other end -- a connector on the SDB, and found the end of that wire was fraying/broken and coming loose from the connector pin. I popped it out and re-pinned it, and now it works fine!
_______ORIGINAL POST BELOW________
My original problem child has reared its ugly head again. It figures, as I have out-of-town guests coming in tomorrow, and a party/tournament coming up on the 23rd.
Anyway, went to play a game on each of my pins tonight to verify all's well ... everything was going great until I got to my Bobby Orr Power Play. GI comes on, but didn't appear to boot up. I opened up the backbox, wondering which error the MPU's LED was going to show me this time.
Well, the LED showed me nothing. Nothing at all. No flicker, no flashing.
I checked all the fuses on the rectifier board; they're good. I disconnected / reconnected all the connectors. No help.
I flipped through the troubleshooting guide I'd printed out, and it mentioned to check the voltage at the MPU's TP2 -- which should apparently be 12V. I'm getting about 1.3 volts, so this seems like a good clue.
It's very late, and I'm overly tired ... maybe I'm missing something simple, but I can't see straight anymore. I won't have much time to work on it tomorrow, as I have to prep the house for guests ... but I thought I'd just throw this out here for some quick troubleshooting assistance, in case I have a few moments to look at it.
(One of these days I'm just going to have to bite the bullet and get an new MPU. This MPU had a fair amount of corrosion damage but I've had it working fine for quite some time now. In fact, I played it as recently as Monday with no problem.)
Anyway, thanks in advance for your help / recommendations...