Do I have a power supply problem?

[dkh]

Hi, guys... hopefully some of you can help me with my PC which is refusing to start. Here's the problem:

For at least six months, I have noticed a barely audible, very high-frequency whine coming from the PC when it is plugged in. Not just when it is on, but the moment the switch at the back of the case (the PSU switch) is turned on. I unplugged the 20+4 ATX connector and 4-pin power connector from the MB and the whine still occurs, so it must be coming from the PSU.

I was away from home for the past four days so I had turned the PC off and unplugged it from the wall outlet in my absence. Upon returning from my trip yesterday, I plugged the AC cord in to the wall and pressed the power switch on the front of the PC case. Nothing happened except I heard the before-mentioned whine. I opened up the case and everything looks normal. The little orange LED near the CMOS battery is illuminated, like it always is when power is supplied to the PSU and the computer has not yet been switched on.

First thing I did was troubleshoot the power switch that leads from the front of the Antec case to the MB by disconnect it from the MB and jumping the + and - terminals directly. This did nothing. Still the same whine; still the LED remains lit.

I then disconnected all the fans (4), DVD drives (2), and secondary HDD from the PSU. Still nothing when I attempted to start up.

BTW, I have been running this build for at least 18 months without problems.

What should I do next?

PC specs:

Antec 500W SP-500 Smartpower PSU
MSI P6N SLI Platinum Motherboard
XFX GeForce 6800 256MB
Intel Core 2 Duo E6600 2.40Ghz
1x1GB Corsair RAM
2x1GB G. Skill RAM
2x250GB WD Sata HDD
Win XP

 

[carnageX]

I'd say its a PSU fault. The whining was from capacitors in the PSU, which could have been dying. Leaving it off could have just drained the caps, and not being able to get power stored in them made them kick their last bucket. Try replacing the PSU and see if that helps.

 

[S0ULphIRE]

before doing that do this:

Unplug the power cord, press the power button.
take out the CMOS battery, press the power button again.
Put the battery and power cord back, then press the power button.

 

[Kharn]

before doing that do this:

Unplug the power cord, press the power button.
take out the CMOS battery, press the power button again.
Put the battery and power cord back, then press the power button.

If it is a PSU problem that will have little effect capacitors charge very quickly and hold a charge for a long time, you might get a dump of power to spin the fans for a second but there still is a **** of a built up charge in them.

I am with Carnage on this one, his trouble shooting meathod is the right one to follow in this situation.

 

[35g700]

I had a similar problem and it was the PSU. I thought it was a bad video card because it would turn on without the video card in it... I Replaced that only to find that it wasn't the problem and it was a bad PSU.

So I'm going to say it probably is your PSU... Do you know how to test one?

 

[S0ULphIRE]

yeah I agree it probably is his psu, but I was just saying it's worth trying before bothering to go out and buy another psu.
see, just because it makes a whining noise doesn't mean it's busted. Most power adapters/converters do, just some louder than others. And it's not just the caps that can cause that noise. Transformers will also do that.

 

[carnageX]

But the computer not powering on at all usually indicates a power option .

 

[S0ULphIRE]

^exactly. I'm not sure whether it's the psu or mobo or what, but one of them has a 'protect' mode, which will stop anything turning on at all. Fans, hdds, leds, etc. Which sounds like what the OP described was happening to him.

Doing what I posted above resets the pc, so it'll actually try to start again. It may turn out the psu is indeed faulty, but it'd kinda suck if it wasn't and all you needed to do was the 'reset' thing.

 

[dkh]

Thanks for all the advice so far, guys. It turns out that the problem is the PSU. I borrowed a spare one a buddy had lying around and the PC started right up.

Now a request for more advice: what PSU should I get now? You can see my specs in my original post. I would like to add another video card so I can run three monitors instead of the two I am currently running. I know everyone says to get the best PSU you can possibly afford, but I really don't want to spend more than a hundred bucks or so. I don't game with my system, but I like it to be stable and I want the PSU to last well in to my next build. Any suggestions?

 

[carnageX]

Newegg.com - Antec earthwatts EA500 500W Continuous Power ATX12V v2.0 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Power Supplies

Antec's Earthwatts series are very good.

Could probably get away with using this one:
Newegg.com - Antec Basiq BP430 430W Continuous Power ATX12V Version 2.2 Active PFC Power Supply - Power Supplies

I know one member here uses the 430 model (pretty sure its the 430 model), and he runs SLI'd 8800GT's on his folding machine.