Can someone help me troubleshoot what's wrong inside my PSU?

[Terrh]

I've done a bunch of googling and ended up here. I've got a non-working power supply that I'd like to fix - or at least diagnose what's gone wrong inside. I voided the warranty shortly after purchase to change the fan because the OEM fan failed very quickly, despite it being an expensive ($89.99) PSU at time.

It's a cooler master 600W "eXtreme power". It had great reviews when it was new - but they had a flaw with the fans, basically all the fans were crap. It's 4 years old.

Anyway, it's worked fine for the most part except for rarely not wanting to turn on.

Well, now the not turning on part seems to be permanent. The fan I put in has a blue LED and when I hit the power button on the computer the fan will twitch and the led will blip on for an instant and then go out, but that's it.

I opened it up, blasted everything with compressed air and had a look around - nothing looks swollen, all the caps seem visually fine. What do I check next? I've got a multimeter that I think has a transistor testing function, but I've never used that part of it.

Or - Should I even bother, or should I just go buy another PSU? I like fixing stuff but I realize that it's not always worthwhile.

Thanks in advance.

[Behemot]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

Well I personally wouldn't buy CM, many of them were just craps, barely arround or exceeding ATX specs, often not providing full power, at least from older reviews I have seen.

May by something else, but I would start with blown secondary rectifiers, the more if you changed fan for one with not enough ariflow (ppl do it quite often, not realizing manufacturer used loud but high-airflow fan for soem reason - usually cause it would cook up otherwise).

Use your diode tester between ground and some wire for every voltage rail, it should read at least 6 or so. If less, try it with resistance meter, if it's arround 1 or 2 ohms, than that particular rectifier is blown.

[Terrh]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

Well, I doubt I'd buy another, but it seemed like.a good idea at the time. The fan I put in has to be better than the broken one that was in it. The psu seems well built from what little I know, just judging by its mass and the huge pile of components inside, as well as the two giant copper heat sinks. I will take some pictures when I get home. Compared to a diablotek $14.99 special that I thought I could replace I it with, it weighs at least double,
The PC it had been connected to hardly put a load on it, probably no more than 200w, if that. Amd athlon 64 x2 and an 8600gt video card.

[svor1988]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

Try heating the PSU up using a space heater. Worked for me. I just needed to raise it up to 70-75F or so. Seemed to me like one of the protection mechanisms on my PSU were triggered when the PSU was colder; causing it to shut off.

[Behemot]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

Cold solder joint?

[budm]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

When you heat up the unit, more likely that it will cause bad caps with high ESR to go back down to low value like it should so the circuits start working again, I use hair dryer alot for troubleshooting cap with ESR problems.
Bad cap can look normal.
Here are bad caps when they are cold:
http://s807.photobucket.com/albums/y...t=DSC00001.jpg
when heated up:
http://s807.photobucket.com/albums/y...t=DSC00003.jpg

[mscserbia]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

Some pictures,results?

[rogfanther]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

That ESR meter looks interesting. Do you have a schematic for it ?

[budm]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

@rogfanther, see here:http://s807.photobucket.com/user/bud...?sort=3&page=1
I built it using 555 as an experiment. Finding the good Meter was the hardest part.

[rogfanther]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

Thanks, it got me some ideas for one, after the holidays..

[ant3202]

Re: Can someone help me troubleshoot what's wrong inside my PSU?

hmm .... i know some coolermaster PSU were made by AcBel...

google UL code / EU

http://www.hardwaresecrets.com/artic...facturer/370/1