mll2k3

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Jul 17, 2009
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I just built my first computer last night. Everything worked normally for about a half hour or 45 minutes or so. I had windows 7 up and running, and was in the process of installing my graphics card drivers. In the midst of this, the computer shut down seemingly at random. I tried to turn the power back on, but nothing happened. Now, I know the PSU isn't dead because the power LED on the mobo still lights up, but the LEDs for the power and reset switches do not. What is going on here?

My system:
COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case
EVGA 512-P3-N954-TR GeForce 9500 GT 512MB 128-bit GDDR2 PCI Express 2.0 x16
Intel Core 2 Quad Q8400 Yorkfield 2.66GHz LGA 775 95W Quad-Core Processor
Intel BOXDP45SG LGA 775 Intel P45 ATX Intel Motherboard
Rosewill Stallion Series RD600N-2SB-SL-BK 600W ATX12V / EPS12V SLI Ready CrossFire Ready Active PFC Power Supply
Western Digital Caviar SE WD3200AAJS 320GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive
Sony Optiarc 24X DVD/CD Rewritable Drive Black SATA Model AD-7240S-0B
EDIMAX EW-7128G PCI Wireless Card

As a novice system builder, I was hoping someone might have an explanation for my power quandary.
 
Another Rosewill PSU bites the dust. You'll notice that no one on this forum will ever suggest a Rosewill PSU. They're junk. The fact that the LED lights up doesn't mean the PSU is still working. The +12V rail(s) on the PSU are what power the main computer components. A dead PSU can put out enough power to light up a light, but not enough to power the system. You can only hope that the PSU didn't take any other hardware with it to the grave. I would RMA that POS for a refund and get a quality PSU from a reputable company like Corsair, PC Power & Cooling, Antec Earthwatts series, etc... Here's one that would power your system just fine:

CORSAIR CMPSU-400CX 400W ATX12V V2.2 80 PLUS Certified Compatible with Core i7 Power Supply - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139008 $59.99 - $10 MIR

You could also try the troubleshooting steps in this checklist, but this sounds like a dead PSU.

http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems
 

mll2k3

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Jul 17, 2009
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This assessment seemed pretty accurate to me, but I have a question: If, when using a paper clip to connect the power-on to the ground, the fan on the power supply spins- should I still suspect the 12V rails in this instance?

Because the fan turns on when using the paper clip to connect the pins. This concerns me because I'm thinking the motherboard is the problem?
 
"should I still suspect the 12V rails in this instance?"
Sure. A PSU fan might pull 1/2 amp. Your computer will need around 20 amps.

As far as the LED on the motherboard is concerned:
A computer PSU has two sections. There's the large, complex main section that provides all the operating power for your computer and a relatively simple, small (10 - 20 watts) 5 volt section that is completely independent called the standby power supply. This is always on. It does things like provide power for "Wake-on-LAN".

The LED is powered from the standby power supply.

But if you think the motherboard is the problem, go ahead and change it.
 

kubes

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It sure does sound like a PSU to me as well. Some other quick things to check would be, did u make sure to install the MB standoffs correctly and have you tried a different outlet in your house?
 

mll2k3

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I mean, you guys know more than I do so I RMA'd the rosewill and ordered a corsair. It should get here today so if that fixes everything fantastic! I just want to have an idea of where to go next if that doesn't solve it.

and yes, I tried numerous outlets and the standoffs are all correctly installed.
 

mll2k3

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Jul 17, 2009
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So, as I feared, the new power supply didn't change anything. When the psu is plugged into the mobo nothing happens, when I take out the 24 pin connector and use a paper clip everything directly connected to the psu (fans, leds) powers on and works fine. Is my motherboard fried?