Random power supply

23-01-2004, 01:18

Just now have had a problem, I think the only reason the PC is on not is fluke.

I'm using a GA7VAX with 2200+ 350W power supply.

The pc just turned itself off, didnt restart. The restart button didnt work. Holding down the soft power did but the pc didnt restart.

I turned the power off at the power supply and back on again. The PC started and rebooted straight away - didnt need to press the soft power button :S

It did this a number of times with varying results with the soft power button and restart button, they sometimes worked, sometimes not. But every time i now turn off the power at the supply unit it starts immediatly.

I had a look at the voltage levels, I have recently installed 2 nics but its been running for over a week with them in, power levels seem slightly low to me - should they be equal to or above?

3.3v = 3.05
5v = 4.59
12v = 12.2
5vsb = 4.8

I had a problem in the past were the HDD indicator light stayed on dim all of the time - i disconneted it.

I cant identify where the fault lies:
- The power unit?
- The reset and soft power switch?
- The front pannel connectors/pcb on the mobo?

Any advise guys? I dont really want to be replacing stuff that might not be broken.

Thanks.

Bifta · 23-01-2004, 01:22

My old machine with a 7VAXP board used to start up on it's own in the middle of the night .. used to get a rare fright, I think that was down to Wake On Lan getting freaky though. It's unlikely to be the power or reset switches or the connectors, it's probably either down to some kind of short in the PSU or possibly a short on the case from the motherboard.

23-01-2004, 01:28

Well at the mo i have things disconnected. Im going to connect the hardware i disconnected earlier and see what happens.

abailey152 · 23-01-2004, 01:37

What other h/w do you have, HDD's, DVD/CD Drives etc. System-wide random faults could be the PSU. If you've got quite a lot running, 350W may not be enough. If you do have quite a few drives etc., then I would upgrade the PSU ASAP as it may cause other damage by pullling too much current if it is being run on its limit.

I've also seen a PSU give problems (shutting down, randomly, not always booting up) in one machine, but be okay when it was tried on an identical machine. Why? Well, just guessing here, but it may have been due to something being out of tollerance, and the mobo being unable cope.

Your 3.3v and 5v do look a bit low, especially the 3.3v.

ZrByte · 23-01-2004, 01:53

http://www.jscustompcs.com/power_supply/

Try this to see if your machine needs a more powerful PSU

you never know an overloaded PSU may be the culprit

23-01-2004, 19:21

Quote:

Originally Posted by ZrByte

http://www.jscustompcs.com/power_supply/

Try this to see if your machine needs a more powerful PSU

you never know an overloaded PSU may be the culprit

Smashing, super, great!

325 Watts

Hmm that should be OK.

I think one switch is def duff in there anyway (main suppliy on/off) so i might try a new one anyway.

Cheers guys

ZrByte · 23-01-2004, 20:45

Quote:

Originally Posted by John Doe

Smashing, super, great!

325 Watts

Hmm that should be OK.

I think one switch is def duff in there anyway (main suppliy on/off) so i might try a new one anyway.

Cheers guys

Just out of interest what PSU are you using?
Is it branded?
Did you buy it sepperate?
did it come with the case? If so was the case cheap or a good brand?
Does it have a Fan built into the PSU?

Im only saying this because my friend has a 400W PSU (Unbranded) wich bails out if you load it at about 360W. wheras I have a 300W Antec wich I have overloaded to 320W and it Ran stable. Just goes to show Quality > Quantity of Watts

Also if you On/off switch is broken try wiring the board to your Reset button instead, it does the same Job and is handy to test these faults with.

23-01-2004, 21:08

its Q-Tec AT-350.

I think i might replace it

25-01-2004, 19:39

Well not so much BANG! as in /sniff-sniff

Yep, small problem with the VCC +5 power.

Dont think it was the supply though, the board must have caused the drain/demand somewhere along the line... ah well

darkangel · 25-01-2004, 20:08

Quote:

Originally Posted by John Doe

Well not so much BANG! as in /sniff-sniff

Yep, small problem with the VCC +5 power.

Dont think it was the supply though, the board must have caused the drain/demand somewhere along the line... ah well

hmmm toasty...u may be lucky and not have damged anything else on ur system moral of the story being don't get a cheap psu, good luck tell us how it goes