5 Oct
2015
5 Oct
'15
1:55 p.m.
One chip getting hot does bother me.
Have you measured the voltage rails.
If the voltage is gone, it may be shorted.
Just swapping it out may not be a good idea unless
you know that it wasn't a failed regulator that
caused it to short out.
Some of the TO-3 type regulators depend on the
screws connecting the case to ground.
I have seen case that corrosion caused by dissimilar metals has caused
the case to float, causing over voltage and damage to the circuit.
I don't know that that is the case of a PET ( don't know
what they use for regulators ).
Voltage checks are always a first.
Dwight