TECH: Asteroids Deluxe (Power Supply Issue?)

Archived from groups: rec.games.video.arcade.collecting (More info?)

I picked up a clean Asteroids Deluxe at the last SA and I'm hoping to
get opinions on what could be causing it to not boot. The game was DOA
during most of the auction preview (both player-lights rapid flash, no
video) but I later saw their tech working on it and when I came back
around, the game was running fine (strong, clean vectors, no obvious
PCB glitches or sound issues).

Now that I have the game home (after running fine for a few hours
during the auction), of course the reset problem has returned.

1. Transformer block: clean, nothing obviously toasted; big-blue looks
recently replaced and is securely connected.
2. AR board: was adjusted up quite a bit when I got it, but I now get
5.2V on the AR board and 5.0 at the PCB edge-connector. I'm getting
12.6 at the 10.3 VDC test loop, though (can't adjust that). Problem?
3. PCB board: 5v LED is lit, 5.0 at the edge-connector and at the test
loop. I'm getting 18.1VAC on pin 20 (actually measured it at the first
cap in) of the edge conn (shouldn't that be 36VAC?) though. I cleaned
the edge connector and checked the harness. The board's clean with no
obvious toasted caps.

If I disable the watchdog circuit (grounded the WD disable loop), the
board runs fine blind... almost (no asteroids, but ship appears
extra-bright and vectors jump around, 4X normal, etc.). Game timing,
sounds, etc. all appear to run fine. Can't see anything while in
test-mode (solid beep), however. Of course, the spot killer LED is on
most of the time. Tried this a few short times with same result. I
also adjusted the +5 at the AR board up and down a bit without success.

I don't have another AR -03 board to swap, and although according to
Alex's site (www.elektronforge.com) I can use my Battlezone transformer
block to swap, I haven't tried that yet.

I'm really thinking that this is a power-supply issue (especially the
12.6v reading on the 10.3v line), but I'm still learning and would
appreciate some expert opinions first.

Thanks.