Power to everything but no boot

[fritter87]

All the fans are running, HDD's are spinning, and CPU lights on the motherboard are lit, but i get nothing on the screen and no activity on the HDD front panel LED. The disk drive will not open, and the front power button will turn the computer on, but not off even after holding it for 20 secs.

Last time it was on, I was playing MW2 and it suddenly shut down completely and the front panel LEDs flashed at a steady 1 sec interval(i haven't been able to reproduce this). There have been no hardware/software changes in months.

I have tried a new PSU but there was no difference. i've also tried removing the CMOS battery for 20 mins with no change. Any ideas would be greatly appreciated.

AMD Phenom II X4 940 Black Edition Deneb 3.0GHz Socket AM2+ 125W Quad-Core Processor HDZ940XCJ4DGI - OEM
MSI 790XT-G45 AM3/AM2+/AM2 AMD 790X ATX AMD Motherboard
2x OCZ SLI 4096MB PC6400 DDR2 800MHz (from older computer)
Stock CPU cooler
HIS H587FN1GD Radeon HD 5870 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card
Rosewill BRONZE series RBR750-M 750W Continuous@40°C, 80Plus Bronze Certified,Modular Cable Design,Active PFC "Compatible with Core i7, i5" Power Supply
Kingston SSDNow V Series SNV425-S2BD/64GB 2.5" Desktop Bundle 64GB SATA II Internal Solid State Drive (SSD)
WD Caviar Green 1TB 32MB/SATA-3G
Hitachi 2TB Serial ATA HD 7200/32MB/SATA-
Windows 7 64-bit Ultimate
Rosewill CRUISER Black Gaming ATX Mid Tower Computer Case with Side Panel Window and Four Fans

 

[etk]

How overclocked were you when this happened? Check your cpu pins for evidence of arcing. Look over your mobo for damaged capacitors. Disconnect everything from your mobo except for the processor, PC speaker and the power supply. Check the status of the diagnostic LED's against the examples in your manual. Are they hanging up on memory test or earlier? I doubt they are getting getting that far, but let us know and we can go from there.

 

[fritter87]

It was not overclocked at all, and i'm pretty sure it doesn't make it to the memory test as there are no beeps from the PC speaker. I'll double check later for damaged capacitors and i'll try running it with the bare minimum and let you know how that goes.

 

[fritter87]

I removed everything but the power supply processor and PC speaker and got no change. I also see no obviously damaged components on the motherboard.

 

[etk]

Looks like either the mobo or the CPU. I would guess MOBo if the CPU wasn't overclocked, but I don't know of a way to check for unless you have another working machine you could test your CPU in.

 

[jsc]

Having two bad PSU's has been known to happen. What brands of PSU's?

 

[fritter87]

I ran both PSU's through a tester both are good.

 

[jsc]

That's really no guarantee. PSU testers can tell you if a PSU is bad, but because the cannot test a PSU under load, they cannot tell you {b]for certain[/b] if a PSU is good.

 

[fritter87]

Best answer selected by fritter87.