Hi, I have a System 11 machine that I have never been able to play. It was DOA.
I have rebuilt the Power Supply with GPE kits (both caps and HV) and changed the headers and connectors.
The problem : I get ~+12V at the +5 outputs.
The signal flow :
About 10.5VAC at the transformer connector (3P1-10 to 12) - that's ok
Goes through F5 and F6 - ok
Goes through the bridge rectifier
I get +13.84VDC at TP3 and -14VDC at TP4 (directly connected to the bridge +/-) - i think that's ok
The + signal then goes to Q5's collector
And this is where it doesn't work anymore.
Q5 gets +13VDC at its base, from IC1, the voltage regulator. (I get +6.61VDC on another working machine)
And I get +12.60VDC at the emitter, instead of something around +5VDC.
I have changed Q5 with another one from a working machine and it's the same results.
Should I change IC1 or there is another possibility ?
Thanks