Looking for something I'm sure I've seen (25c)

[[kby]]

(06-07-2019 04:31 PM)BobVA Wrote:  I'd be suspicious of the ACT chip, which can malfunction in a surprising number of ways.

If you have some basic troubleshooting experience and the equipment, you might want to check the outputs of the power supply to rule that out. The HP-25 schematic
here has the necessary information.

Replacing the ACT didn’t change the symptoms. Found a disintegrating resistor, but replacing that didn’t change things either.