I'm working on a Taito Captain Zodiac punching machine and I'm trying to isolate the cause of an issue with the following symptoms;

1. If the machine has not been turned on for a while, then when I turn it on, I get all sorts of action, lights, solid state relay trigger, motor movement, and action on the DMD (garbled) but this lasts for about 30 seconds and then goes to no action at all.
2. If I reset the machine (i.e. turn it off) then I get no action at all - no DMD lights. All I get is some speaker humm.

Things that I have tried changing & swapping but have given the same result.
-Re-programmed the EPROMS with the dump that has just come from MAME (I suspect my ROMS were bad as they had been uncovered)
-Change the main 220V-100V AC Transformer
-Switch DC Power supplies.

Below is a link to the manual which has fairly comprehensive schematics;

My suspects are;

  • The 18V transformer
  • Bridge Rectifier
  • AC Noise Filter
  • 22000UF Capacitor
  • Maybe the PCB?

Any suggestions?