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System too weak for PSU?

  • Power Supplies
  • Computer
  • Components
Last response: in Components
March 21, 2008 2:48:40 PM

I'm having big problems trying to figure out why my computer wont boot. I bought a TT toughpower 700w PSU because my old one started to make annoying noises. Here is my (oldschool) setup:

AMD Barton 2500+ @ 3200+
Asus A7N8X-E Deluxe
2x256MB ram
Radeon 9800 Pro
2x WD 250GB HDD
2x optical drives
Fanbay, that powers 1 12CM pabst fan

When I try to power on my computer nothing happens. I can see that the fanbay-leds shortly flash, but then dies. If I disconnect the fanbay and put the fan directly on the mobo, the fan runs, but the harddisks and everything else doesn't. There's a wierd thing. One of the optical drives lights its front LED, but it can't open or anyting..

When I put my old PSU back in everything works fine (except for the noise ofcourse). Any ideas?

Ofcourse with this setup I'm not using the PSI-e connectors from the PSU, but should that have anything to say? I've also tried to put all the HDDs and optical drive + gfx on one 12V rail just too try someting - but nothing happens.

Any help would be greatly appreciated as I've already traded the PSU for a new one once :( 

More about : system weak psu

March 21, 2008 3:15:16 PM

Your New PSU is likely DOA.
Return for a new one.

It has more than enough power, it's just faulty.
March 21, 2008 4:23:38 PM

Well the thing is I've already returned it once for a new one. So it can't be a faulty PSU.. Anyways, I'll try and put it in another system to see if it works there, just to confirm 100% that the PSU works..

New input still greatly appreciated.
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March 21, 2008 5:04:09 PM

toblundI I would buy a atx 12v power supply tester,I think they sell for about $15.00 .and you should find them at any electric store,or even best buy ! really the ps you brought is a over kill for those spec's.hope this help you.good luck
March 21, 2008 5:38:50 PM

Well, I just tryed the PSU in another PC with very similar specs to my own. And it works fine there.
So now I'm stuck. Can it be some compenent in my system that causes this newer PSU to shut off because of some fault voltage even though my old PSU doesn't detect it?
Or can it be a motherboard compatability issue?
March 21, 2008 5:59:47 PM

Try clearing the bios.
March 21, 2008 6:01:37 PM

Did you plug in the 4 pin power connector?
March 21, 2008 7:37:49 PM

Ok I'll try cleaning the bios and install the new PSU.

No, there is no 4-pin connector on my motherboard. It's just the 20 pin.
March 21, 2008 8:52:53 PM

Tryed clearing the bios.. Still nothing. When I push the power butten it just briefly turns on then shuts down instantly.
Really frustrating. Well, I think I'll try trading it for a Corsair 750TXEU tommorow and see if that will work.
March 21, 2008 9:32:09 PM

Try disconnecting ALL components except CPU/HS, memory and motherboard.
Try running with motherboard outside case, you may have a short, that could be what is causing original PSU to make noise if it is not tripping out.

a c 86 ) Power supply
March 21, 2008 9:37:04 PM

Its not the psu(as such) antec 380 buzzes like a bastard on a celeron 466, but my 90 watt is silent....It even buzzes on start of my E6600(just cpu and board) with a weak pci video card. but as soon as everything powers it stops.

My brothers psu buzzes too untill you open a game and increase the load then it stops(he does not care and its been over a year like that anyway. turn up the sound)....

I know this looks like a flaw, but coils do buzz(this includes the ones on video cards and motherboards sometimes) and at low loads they are in your hearing range. Some psu's will not be effected by this.

I would almost say try an Antec earth watts 430(or 380 if you do not plan to upgrade to far) since it still has more then enough power and should be quiet. My a64 3200+(under volted :)  ) with gf4 4200+ is a lower load(about 100 watts folding) so if that does not buzz....well yeah..

So at low power some units will buzz.....but not all will...
March 21, 2008 10:10:53 PM

Oldschool, LOL I think they have a place for that in the Smithsonian right between the Altiar 680 and the Cray.

Just kidding, if it does everything you ask there is no need to update.

As for your problem the 700 power supply could be putting out to much juice for your system thus tripping its protection. I agree with Nukemaster.
March 21, 2008 10:48:45 PM

toblund I have to agree with the master

I would almost say try an Antec earth watts 430(or 380 if you do not plan to upgrade to far) since it still has more then enough power and should be quiet. My a64 3200+(under volted :)  ) with gf4 4200+ is a lower load(about 100 watts folding) so if that does not buzz....well yeah
March 22, 2008 12:26:50 AM

It's "power on" circut (in the PSU) might not be getting the "ok" in time. Try holding the power on button in for a full sec and see if it boots...if not return it.
a c 86 ) Power supply
March 22, 2008 6:26:15 AM

Tried my Antec 380 on a celeron 266(yes i still have one kicking around) no go(no post fans spin up..)....250 watt FSP and 250 watt hipro both run it fine....its odd, but it happened....i wish i had a technical reason...
March 23, 2008 3:23:41 PM

I traded the toughpower 700w for a corsair 750TXEU - still the same problem. Except this times it's runs a few seconds longer before it shuts off. I even had my mobo out of the case and it doesn't help either.

So it must be something wrong with the mobo that my old PSU can't detect, but the newer ones will detect it and shut off.

So, I could buy an older PSU (or maybe just cheaper). But I think it's about time to upgrade my system anyway, so I'm keeping the corsair 750TXEU and buying new CPU, mobo, gfx and RAM..

Thanks for your input guys!
a c 86 ) Power supply
March 23, 2008 4:49:38 PM

That corsair is a MONSTER so keep it for future use...think quad sli/crossfire and quad core :)  and still power left.

Almost any psu should auto shut down if it detects a fault.....when if goes off can you just hit power to try again. when a psu trips normally you have to remove the power for 30 seconds(to let the self resetting fuse reset) or so before it will go again.

One thing that i can think of....some older board may have used the -12 and -5(yes negative) volt lines. The -5 was remove from the ATX specs for version 2.0. Since all psu's are now 2.0 that line is a goner.

Your system is not overly power hogging. Why not try to change the fan on the original psu and just keep an eye on it...

When i get a chance i will try to power my Athlon XP 1800+ ECS K7S5A on a new psu and see what it does....
March 24, 2008 4:03:35 PM

When it goes off it can't be turned on again intill I flick the switch on the back of the PSU to "off" position for a few seconds..

Maybe you're onto something with the -12 and -5v thing. But could that make a newer PSU shut down you think?

I will try and look in the manual for my A7N8X-E DeluXe too see if it need the -12v and -5 lines.

Ok I reconsidered buying all new system. But I don't think changning the fan in the PSU will do anything because it's the noise is a very high-freqenzy noise so I think it comes from a capacitor. But I'm going to try and find an older - non atx 2.2 - PSU and see if it'll run.

"When i get a chance i will try to power my Athlon XP 1800+ ECS K7S5A on a new psu and see what it does...."

That would be interesting to see! :)