dead ROM comes back to life!

scorpiistar · Joined: Feb 28, 2007 Posts: 9 Location: australia

something strange happened, that deserves reporting......

I was soldering wires onto a casio rom, forgot to turn the power off, and.....well.....it fried there was nothing left but shitshots.

how it came back to life.....i grounded the pin i was soldering and the shitshots sounded less shitty

i had an idea that if it was just the one pin and i fed a stream of ones and zeros down its track to the CPU chip, maybe it wont know the difference :/

consult service manual for ideas & tried main clock, main clock/20 test point, DAC word clock, all shitshots........then

DAC serial data line from CPU gave me a distorted piano sound! threw on a 1k resistor and a steering diode and it was back from the dead........100%

anyways i got lucky........but for anyone with a similar issue with an irreplaceable vintage ROM it might be worth a try