Re: Help sought with 128k+ repair

Aly escribió:
for the RS232 signal generation?? All the logic, ram etc. will be bipolar
5v??

I can't see any vital component tied to anything other that the +5V line, but... have you checked that you have 5V? A damaged TR4 for example, can drop the voltage on the 9V line down to a level that the 7805 cannot handle. Also, I'm assuming that you are using the right power source, as the schematic states that the +5V supply should give 3 amps (although I think that 1,5 amps is enough for a bare system)
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