YesAffinity
Enthusiast
Got this A board on the cheap, as non-working. I’ll say! Right off the bat, I could see things visually damaged – a mangled connector, mangled perimeter ceramic cap (not shown), volume pot bent over and one of the legs busted off, a couple caps that have sustained impact and damage.
Got those all fixed up, try to power the board and it is immediately shorting my power supply. Disconnect the board, checked each voltage line at the jamma edge connector on the board, and find +12V is shorted to ground somewhere. The hunt begins.
Thankfully, it was a +12V short and not +5V, because there’s not much to the +12V circuitry. There’s the audio amp, some M5218’s, associated caps and resistors, and a voltage regulator. Started removing things one part at a time.
Finally figured out that I had it isolated to the circuitry coming off of jamma pin F. Removed way too many components before I realized it, but once I made the realization, I got right to the culprit - CC20 was closed.
Reassembled the board, including replacing CC20 from a parts board. Game booted up, but I’m immediately greeted with the next challenge.
Likely a faulty CPS-A-01. (Isn’t it always?
)
A little bit of finesse with the ol’ hot air station, and this A board is good as new.
Got those all fixed up, try to power the board and it is immediately shorting my power supply. Disconnect the board, checked each voltage line at the jamma edge connector on the board, and find +12V is shorted to ground somewhere. The hunt begins.
Thankfully, it was a +12V short and not +5V, because there’s not much to the +12V circuitry. There’s the audio amp, some M5218’s, associated caps and resistors, and a voltage regulator. Started removing things one part at a time.
Finally figured out that I had it isolated to the circuitry coming off of jamma pin F. Removed way too many components before I realized it, but once I made the realization, I got right to the culprit - CC20 was closed.
Reassembled the board, including replacing CC20 from a parts board. Game booted up, but I’m immediately greeted with the next challenge.
Likely a faulty CPS-A-01. (Isn’t it always?
)A little bit of finesse with the ol’ hot air station, and this A board is good as new.
