Tesing a PSU - Edit: Tested - are these voltages close enough?

[3chordcharlie]

I've got a system with a PSU I'm getting suspicious about.

It always used to have random reboots, which I blamed, finally, on the motherboard. I replaced it, and it's been quite stable. But now the usb-header has burned out on the new motherboard(and I mean burned; there's a black spot). I never considered the PSU because it's a 350W Enermax, so there was no reason to suspect it would be faulty.

There's never been so much as 1mhz of OC on this PSU, or the board, and it has always run hot (even with the old board); the air from the psu fan is noticeably warmer than from any other computer I own (including another AXP system with a 300W enermax). I would almost call the air 'hot' but it's definitely warm.

Is there any way to test this thing? I'm already going to be out $100 if the motherboard can't be returned under warranty (I didn't do anything wrong, but the burn mark may suggest otherwise); I hardly want to spend another $60-100 for a decent PSU if the old one may be fine.

 

[oneshot47]

get a cheap multimeter and check the voltages. unless you spend some money though, you probably wont be able to check the amperage on the lines, most cheap mm's only work in the milliamp range and you need something that can handle 30 amps or so. if the voltages are within 5% though, thats a good sign.

 

[3chordcharlie]

3.28
4.86
11.47

doesn't sound too good

Double checked on my other xp1800 (w/ 300W enermax) and the 12V rail is 11.7. So I think the one in question is probably bad.

Both checked at full load.

 

[3chordcharlie]

Bump for morning - hot likely is it that the above voltages indicate a problem with the PSU?

I already need to replace the mobo (hopefully under warranty) but do I need a new PSU as well?

 

[oneshot47]

Those are all within 5%, but the 12v line is on the low end of that. The best way to really know would be to use another psu (borrow, steal, whatever) for a little bit and see if it still randomly reboots.

 

[Rukkian]

Those numbers are fine as long as they dont fluctuate. It may just run on the low side. As long as there arent spikes up and down, that should be fine.

 

[3chordcharlie]

Originally posted by: Rukkian
Those numbers are fine as long as they dont fluctuate. It may just run on the low side. As long as there arent spikes up and down, that should be fine.

Thanks - they're quite stable, and that is at full load, so I guess it's as bad as it gets.

Since it's a good brand, I'll try to get just a new motherboard, and maybe install an extra case fan to deal with the air temperature coming from the PSU.

@oneshot47 - it was a previous motherboard that had the reboots; I just don't want to wreck another one if it could be the PSU, so I'm trying to decide if the burned out USB ports were just a bad mobo (happened in the first month) or PSU-related.

Looks like it's probably just a deective mobo.