Received this quite rare Hard Puncher (on Konami Twin16 hardware) for repair:
PCB failed all the time the self-test showing a bad device @10G on CPU board and then resetted, this in an endless loop:
The involved device is a Mitsubishi M5M5165 (8K x 8-bit static RAM) compatible with 6264 :
Its data bus showed no activity:
The chip failed the out-of-circuit test each time in a different address location:
With a good RAM the board successfully booted into game:
But speeches were missing, here is a comparison with a MAME recording:
I quickly pinpointed this fault in a missing 640KHz ceramic resonator, this is for generating clock to the uPD7759 ADPCM speech synthesizer IC.I took a spare from a dead Sega System16B motherboard:
One Response to “Hard Puncher repair log”
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Ah ah, this damn 640kHz cristal.
It sticks out a little bit too much of the top board and get ripped so easily.
The last 3 Twin 16 boards I fixed had it missing!
See my last Devil World repair.