I recently purchased a non-working Bally Home Library Computer / Professional Arcade / Astrocade system. On power up it would only show a black screen. I found that the original power transformer had no voltage output, so I'm going to start there. It's a really odd transformer with 2 center taps (4 pins output.) The correct voltage from the transformer should be |-10.8-|-7.5-|-10.8-| VAC. It's rated at 85mA for the 10.8v and 1 A for the 7.5v. The astrocade main circuit board has the bridge rectifiers and voltage regulators on it, plus two massive capacitors.
I found a very good schematic on this page: http://www.ballyalley.com/documentation ... 011%29.pdf
It seems the problem is the Astrocade has weird voltage requirements. +15v, +10v, +5v, and -5. WHY!?! I'm also confused about the 15v regulator's existence, I can't see anything that requires it on the schematic!
My question is: could I replace the original AC transformer with a more common |-12-|-0-|-12-| or |-9-|-0-|-9-| center tap transformer? I'm also thinking of forgetting the original power supply altogether and applying the required voltages directly to the board, maybe by adding a colecovision plug.
From what I've read, the Astrocade was the XBOX 360 of its day in terms of reliability. It was very prone to overheating, especially early models.
If anybody has any tips or advice I would appreciate it.