Philips PM-3323 DSO Blowing Fuses

you may have a resistor or some diodes shorted, surely one or more diode.. easy to check with a multimeter... verify all big resistors ans all diodes as you can have more than one shorted... also check the main transistor which is probably shorted too.

Thanks, that's what I plan to do but thought I'd start a trawl for info/schematics anyhow. It's a bit more complex than normal as the EHT supply seems linked to the main switcher as well.

Jim

what is the integrated circuit assuring the oscilator function in your supply ?

I don't know yet, I have still to work out how to disconnect the on/off mechanism - the rod to the front panel goes through the PCB.

Jim

"Jim Attfield" a écrit dans le message de news: snipped-for-privacy@4ax.com...

A few years ago I reversed the PM3320A PSU. I still have the schematics, but looking at it I didn't completly finished the work. AFAIR it finally was the EHT transistor that was fried and made the main PSU have vapors.

The 3320 and 3323 share a lot and almost surely have identical supplies. Even if the schematics isn't completly finished (maybe up to 95%), it'll be useful. I send you a copy.

In response to what Fred Bartoli posted in news:44704295$0$7100$ snipped-for-privacy@news.free.fr:

PM3335 manual and circuits here: ftp://bama.edebris.com/bama/philips/pm3335/PHILIPS%20PM3335-37-SM.djvu

Fred, that's brilliant - can't thank you enough.

Jim

Thanks anyway, but I was after PM3323 and nothing there is close enough I'm afraid.

Jim