On 9/24/2020 8:18 PM, Phil Allison wrote:
David Farber wrote
==================:

Before I went to the trouble of dismantling my audio dummy load resistor
setup, I found two, 3.3 ohm, 1 watt resistors, put them in series, and
soldered them in place of the thermistor. (My supply of resistors in the
low ohm, high power range is almost nil.) I know you said to use at
least a 5 watt resistor but I wanted to get some idea of what kind of
current the amp would draw on power up. I did put a 200 watt lamp in
series.

** Completely spoils the test.


By the time the line voltage was up to 50 ACV, the lamp was
glowing at about half strength and the AC current was about 1 amp.

** So nearly 50V AC was across the 200W lamp.

Odds are very high the PSU is a dead short to the AC supply - though the bridge rectifier may be OK. Check that and some FETs with a multimeter on diode tests.



.... Phil


I will recheck for shorts in the PSU.

Thanks for your reply.
--
David Farber
Los Osos, CA