PSU sudden death twice !(help pls)

[drebel]

It's about a Power star 375watt PSU ,put on a KT7A-raid with a Barton 2500+ @2266 ,4 fans on board and 3 external fans,plus 3 HDDs and a Geforce2MX.
When I put vcore=1.85 volts, PSU dies after 5 mins of heavy load (prime95 or hotcpu tester pro) .Same way I killed my second psu (RMA)
Now I'm with my old PSU (250 watts!!!) but I'm having undervoltage problems (down to 1.82 in some cases instead of 1.85 ), so I'm not stable in that speed.
I was tempted to open the damaged PSU ,so I did .Guess what: the two aluminium sinks where HOT , even if the internal fan was working fine until the sudden death.Everything else seemed fine (no melted parts of funny smells ) but nothing is working.On the PSU's cover it says "temperature controlled", and on the side :

+5volts: 35A
+12volts: 17A
+3.3volts: 28A , and a large Pentium4 sign

model number: ATX-375C12 (PFC)
Any ideas? Any help would be highly appreciated ...

 

[Crism]

maybe get a better brand psu? antec, enermax, and vantec are all good....

 

[phoenix111384]

or fortron (cheaper then what was named, but higher quality). you get what you paid for

 

[dukla2000]

...and on the side :

+5volts: 35A
+12volts: 17A
+3.3volts: 28A , and a large Pentium4 sign

model number: ATX-375C12 (PFC)
Any ideas? Any help would be highly appreciated ...

More interesting would be a "+3.3V plus +5V combined max power" rating - 180W would be about right.

ATX spec states psu should shut down on overload - if you unplug the AC, wait a minute & try again does the psu work? If so it is sensing an overload and behaving 'as designed'. Would have thought those components are well within a 180W combined load so you could have some other component flaking out.

 

[drebel]

No resurrection after THIS death ,I'm afraid...
There 's no indication on the PSU about the combo ,either.Is there any way to remove this sensor ?

 

[Oklahoma Wolf]

There's no way to easily remove the internal protection circuitry, and I wouldn't do it even if I could. It's there for a reason - to keep the unit from dying as spectacularly as a Deer (lots of fireworks).

I've never heard of Power Star - it's likely not a good unit to begin with, especially since the 3.3/5 rating is missing. It could be made by some other company though - one way to check is to take the UL file number (E123456 for example - should be under the UL logo on the label) and do a search at www.ul.com in their certification directory.

 

[drebel]

I think I found it :
http://www.datafile.de/fsp
the 375 version with PFC.

 

[dukla2000]

Fortron Source Power make some of the best PC psus, including FSP, Sparkle, AOpen, Nexus & Zalman.

If a psu shuts down from overvolt/overcurrent, it is supposed to reset after power is removed. So in your case where it is not recovering there is a bigger reason.

Another psu safety device is an AC overload fuse. As you have already opened the psu your warranty/RMA options are zero, so you may as well check the fuse inside (often soldered to the circuit board) and replace it if blown with an identical one. The sizes are usually printed on the pcb (e.g. 4A for 300W, 8A for 400W etc). Except replacing a fuse, even if it brings the psu back to life, does not resolve the root cause. (Which could be a bad psu or some other bad component. In theory a complete overload, but if your 250W psu is surviving then I doubt it.)

Except I would doubt very much your psu is FSP: I have never seen a 375W FSP (they do 250, 300, 350, 400 etc). Also, being a 'better' manufacturer they always quote the 3.3 & 5V combined (this is relevant as those 2 rails share an AC/DC transformer). The site you link to is indeed supplying FSP psus (probably with quieter fans) except I see no 375W flavour. Also FSP psu part numbers nearly always start FSP... I suspect in the absence of a 'proper' label and a part number that starts ATX you have something else. As per Oklahoma Wolf you could try trace via a UL number but the short answer may be (another) new psu.