Discussion Category: Centrifuge
Diffusion pump heater band
..doesn't turn on. I was able to trace back from the heater band to the power relay to the transistor array to the CMOS chip to the D6 pin on the Motorola M68000 CPU on the daughter board. The connection is all good. It's just this pin doesn't go high. (Or it could be a problem with the CMOS chip.)
I feel it's probably a problem with a temperature sensor that is preventing the logic to go high, but I don't know where to look for.
A workaround would be a jumper wire from 5V supply (or the signal for the vacuum pump) to the input pin of the transistor array so that the heater band is always on, but I am not sure if that would cause another problem.
I would appreciate any insight into this problem. Thank you.
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