Re: FSP400-60GLN worth fixing?

Well actually the PFC was doing its job
In my PSU the target boosted VB set is 380V and the CM6800 switches OFF with VB below 180V.
Even with very light load (the PSU fan for instance) the PFC tries to boost VB drawing too much current with the light bulb in series. So mains input voltage drops, VB decreases down to 180V and PSU switches OFF. I think the same happens with the broken Q61.
Without any secondary load, VB reached 380V slowly (after several seconds), then when light was OFF I added loads and it was OK, the light remained...

Re: FSP400-60GLN worth fixing?

Update: I put a pair of TK17A65W and tried with a 100W light bulb in series: after I turn on the PSU the light is very bright even with no load, maybe this is due to the PFC? Output voltages are OK, a small 12V fan is OK, but if I add a HDD the PSU turns off.
Actually I remembered that was the same behaviour before the PSU died the first time: it didn't start in a full system, but the PSU fan was OK and failed only with a HDD, until Q61 died.

Then I removed R8B to disable the PFC and now the PSU is OK with the HDD, there is only...

Re: FSP400-60GLN worth fixing?

Yes, in my PSU Q60 and Q61 are Fairchild FQPF13N50C which cannot be found anymore.
Does anybody know what other MOS are mounted on this kind of PCB (>=400W configurations)? Or a good cross-reference suggestion?

Re: FSP400-60GLN worth fixing?

Hello Behemot,
don't bother to unsolder your transformer, I think I found the culprit: Q61, it's neither open nor shorted that's why I didn't find earlier...

Re: FSP400-60GLN worth fixing?

That would be interesting, I think this is the kind of tester I have too ( [url]http://www.dx.com/p/transistor-tester-multi-functional-lcd-backlight-didoe-triode-capacitance-resistor-esr-meter-414196[/url] ), thanks!Re: FSP400-60GLN worth fixing?<br />...rl] ), thanks!Re: FSP400-60GLN worth fixing?

That would be interesting, I think

Re: FSP400-60GLN worth fixing?

Hello,

I have a 2006 FSP400-60GLN which +5VSB is OK but main PSU doesn't start (after 88ms the PS223 undervoltage condition is triggered, +5 and +3.3 are below 2V, +12 below 5V, +5VSB still OK, VCCP is 15V)
Primary and secondary sections seems OK, PFC during startup rises from 325 to 375V (230V mains here).
Opto M2 in the feedback loop is OK but CM6800 still skips cycles before being stopped.
I was wondering if the primary of the main transformer (SPI 8TG00171) is shorted which would trigger the DClim protection...