I brought home a non-working Galaga. Replaced the power cord and it powered up. There was sound and picture but the fighter was upside down as was the high score display and this was at the bottom of the screen (credits were at the top, upside down). Controls didn't work either. The enemy bees were ok though. So I turned it off to "reset" it. Turned it back on and get no sound and only white screen.
Bought a switching PS with the adaptor from Arcade Shop. I'll be rebuilding the original PS someday, just wanted to get it running for now. I pulled all socketed chips and cleaned their legs. Reseated and double checked my work. It powers up and looks really good and can play but has no sound other than the explosions when fighter is killed.
I bought and replaced the proms at 1D and 5C (from Bob Roberts) after researching this issue but it didn't change anything. One thing I've noticed is that with the switching PS I get the +5v but the +12 reads at 14.2v both at the switcher and the 3 pin molex connector on the PCB. I can't get close to +12v. I can lower the +5 to 4.8v but that only brings the +12 down to 13.XXv (can't remember exact numbers and I'm at work now). Is this a problem? Having the +12 that high? Did I get a faulty switcher?
What else could be causing the no sound issue? Would a CAP kit for the PCB help?
Any ideas/suggestions/comments will be greatly appreciated!
Bought a switching PS with the adaptor from Arcade Shop. I'll be rebuilding the original PS someday, just wanted to get it running for now. I pulled all socketed chips and cleaned their legs. Reseated and double checked my work. It powers up and looks really good and can play but has no sound other than the explosions when fighter is killed.
I bought and replaced the proms at 1D and 5C (from Bob Roberts) after researching this issue but it didn't change anything. One thing I've noticed is that with the switching PS I get the +5v but the +12 reads at 14.2v both at the switcher and the 3 pin molex connector on the PCB. I can't get close to +12v. I can lower the +5 to 4.8v but that only brings the +12 down to 13.XXv (can't remember exact numbers and I'm at work now). Is this a problem? Having the +12 that high? Did I get a faulty switcher?
What else could be causing the no sound issue? Would a CAP kit for the PCB help?
Any ideas/suggestions/comments will be greatly appreciated!

