Good advice Burt. While we're on the subject of over-heating issues, on instruments with fan filters, I'd like to mention the importance to clean their fan filters at regular intervals.
See: http://www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1995-01-03.pdf Greg --------------------- Burt wrote: ...One day whilst I had my back turned on it the pass transistor in the power supply shorted and in turn took out most of the devices on the mother board turning the mother board into a wind chime vane. I was fortunate enough to find another mother board, replaced it and it now was up and running again but still too hot in my ongoing opinion. Here's what I discovered: On the rear of the HP-3336A are two power selector switches. Instead of mine being set to 120 VAC I discovered they were set to 100 Volts. I don't know why or how they came to be set at 100 VAC since the instrument came from a local engineering firm, not Japan. Maybe somewhere along the way one of the switches simply got bumped. Anyway, it was just one position off from where the combination should've been set. Correcting the primary voltage selector cleared the heat problem and the instrument, with my monster heatsink, now runs quite cool. So, for whatever little bit it might be worth, if you think it's running unusually hot, check the voltage selector switches on the rear and possibly the primary DC voltages into the regulators. --------clip-------- _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.