This is a story of a pile of boards here and the story begins with "I have a trade for you", which now brings to mind this:
I grabbed the only set of boards screwed together and gave it a glance and thought, this would be the quicker repair.
OOPS.
Repair log is here
The first clue should've been the wonky soldering on the audio amp and when I separated the board stack, the bottom of the board was black and two traces were missing. Second clue should've been that they had added solder to the edge connector pins. Third clue was that they replaced the 28, 40, and 42 pin sockets on the board, but not the 24 pin ones.
Well, there are only 5 electrolytic caps on the CPU board, how hard can it be to replace those? Urg. They replaced 4 of the 5 with radial caps. No problem, I replaced those with the proper axial since I have a pile of 'em here. The audio amp was still red hot. A quick meter check showed one of the outputs was shorted to ground. The only cap they installed that was of the correct type had a solder bridge from the audio output trace to the ground pin of the cap. OMG.
Removed the short. Removed the audio amp chip and the legs just fell off of it from all the heat damage. The ground trace on the top of the board was not there. Rebuilt the ground trace using copper tape, installed a replacement amp, and patched the two damaged traces on the bottom of the board.
Still dead.
Patched a missing ground pin on the 06XX chip and replaced the damaged 28 pin socket. Board looked dead, but suddenly "Boom!" - it had sound and played blind.
Checked the video board and found 5 missing pins on the 05XX chip and a wire pin on the 07XX. Patched the pins on both chips, replaced the 24/28 pin sockets, cleaned the customs, and replaced the old style resistor packs. Tested. Game now works.
Replaced the 24 pin sockets on the CPU board and retested.
Moral to this story: If you f*** something up, check the work you did.
If you can't figure out what you broke, then it'll just take me longer to find it and fix it.
I know the person who brought this pile of boards over didn't do the work on this boardset himself. Not sure where he got it from, but when he gets it back, it'll be a nicely working boardset.
Just had to vent!
RJ
PS: If you're a n00b, don't work on Galaga boardsets. They are EXTREMELY easy to bridge solder on as there are many traces next to solder pads that aren't covered with the green solder mask.
I grabbed the only set of boards screwed together and gave it a glance and thought, this would be the quicker repair.
OOPS.
Repair log is here
The first clue should've been the wonky soldering on the audio amp and when I separated the board stack, the bottom of the board was black and two traces were missing. Second clue should've been that they had added solder to the edge connector pins. Third clue was that they replaced the 28, 40, and 42 pin sockets on the board, but not the 24 pin ones.
Well, there are only 5 electrolytic caps on the CPU board, how hard can it be to replace those? Urg. They replaced 4 of the 5 with radial caps. No problem, I replaced those with the proper axial since I have a pile of 'em here. The audio amp was still red hot. A quick meter check showed one of the outputs was shorted to ground. The only cap they installed that was of the correct type had a solder bridge from the audio output trace to the ground pin of the cap. OMG.
Removed the short. Removed the audio amp chip and the legs just fell off of it from all the heat damage. The ground trace on the top of the board was not there. Rebuilt the ground trace using copper tape, installed a replacement amp, and patched the two damaged traces on the bottom of the board.
Still dead.
Patched a missing ground pin on the 06XX chip and replaced the damaged 28 pin socket. Board looked dead, but suddenly "Boom!" - it had sound and played blind.
Checked the video board and found 5 missing pins on the 05XX chip and a wire pin on the 07XX. Patched the pins on both chips, replaced the 24/28 pin sockets, cleaned the customs, and replaced the old style resistor packs. Tested. Game now works.
Replaced the 24 pin sockets on the CPU board and retested.
Moral to this story: If you f*** something up, check the work you did.
If you can't figure out what you broke, then it'll just take me longer to find it and fix it.
I know the person who brought this pile of boards over didn't do the work on this boardset himself. Not sure where he got it from, but when he gets it back, it'll be a nicely working boardset.
Just had to vent!
RJ
PS: If you're a n00b, don't work on Galaga boardsets. They are EXTREMELY easy to bridge solder on as there are many traces next to solder pads that aren't covered with the green solder mask.
