The schematic located in the service manual for this power supply has a logic error: on page 128 (BIAS SUPPLY) it shows that U11 pin 1 (DELAY) is connected to the micro's reset pin. This is incorrect. U11 pin 5 (RESET) should be connected to the micro's reset pin. I have verified that this error also exists in my power supply - it is mis-wired/routed. I've re-worked my power supply to correct the issue when it had stopped working, but the LM2925T's RESET output does not drive to a proper logic
- It only gets to about 2 volts. The problem is that the LM2925T's internal pull-up is only 30K. Since it is driving a 80196 as well as an ASIC, this was not quite good enough. Solution: I added an external 4.7K resistor to the micro's reset line. The power supply is now operational.