System shutdown for no reason...now won't post

Hi All,

As the thread title states I had a spontaneous shutdown.... Had been working great for over a year before this. I was simply surfing around when my entire system shutdown without warning of any kind. At first I though I had tripped a circuit breaker because of the suddeness.
When I tried to boot the system up again, the power and hdd LED comes up on the front of the case, the CPU fan, case fans and PSU fan seems fully functional, but my computer will not post or beep at all. Nothing on the monitor either.

Here's what I've found so far...

- my power supply is reading 4.9V on the +5V supply connector
- I'm reading 13.05V on the +12V connector (not sure if this is outside spec. or not, or if this could've caused my problem)
- I removed all peripherals - DVD player and burner, all but (1) memory module, sound card, wireless card and video card, reset the CMOS and tried to boot using on board video.... no luck.

When I removed the video card, I noticed a blown capacitor. I'm not sure if the current failure is related to this or not at this point, but is does seem like a strange coincidence.

So any ideas what I might be looking at as the culprit? Is my PSU toast? My motherboard toast? Any chance my it's my CPU? Test ideas?

Any help or insight would be greatly appreciated. Here's the build info...

Mushkin 2GB (4 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
Western Digital Caviar Black WD5001AALS 500GB 7200 RPM SATA
ASUS VH226H Black 21.5" 2ms(GTG) HDMI Widescreen LCD Monitor
Gigabyte GA-M61P-S3 AM2 NVIDIA GeForce 6100 / nForce 430 ATX AMD Motherboard
AMD Athlon 64 X2 6000+ Windsor 3.0GHz Socket AM2 125W Dual-Core Processor
XFX GeForce 8600 GT 256MB 128-bit GDDR3 PCI Express x16 SLI Supported Video Card
Rosewill RX750-S-B 750W 80Plus Certified, ATX12V v2.2 & EPS12V v2.91


Thanks in advance for all feeback!

Hi, Thanks for the quick response.

I didn't realize at the time that I did this build that the Rosewill was a bad choice for a power supply. Next time I will know better...


Maybe I wasn't clear on the steps I've taken up to this point.

To clarify a little bit....

- I didn't use my voltmeter to measure that voltage. I used the power supply to power another MB, CPU and HD and was able to get that unit to POST so i could observe the voltages in the BIOS

- I reset cleared the CMOS and plugged my monitor straight into the onboard video connector on the motherboard and still can not get the computer to POST. I'm assuming that by clearing the resetting the CMOS my BIOS should have gone back to default setttings and allowed my computer to boot if it was a video card related issue.

- I hadn't noticed the blown capacitor on the video card until I removed it when I started troubeshooting

Any ideas? I'm leaning toward replacing the motherboard at this point.
Or should I just suck it up and replace the motherboard, video card and PSU all at once. I'd prefer not to if I didn't have to.