Comp crashed, now no beeps, no picture, fans/lights still work, vga fan full speed

[Slider821]

Hi, my comps details:
built myself 2 years ago(5th build of mine)
intel e6850 core 2 duo 3.0ghz
asus p5n-e sli mb
2x2gb corsair 800mhz ram
wd 500gb sata hd
bfg 9800 gtx oc 512mb pcie card
450w ocz power supply
xp

Problem:
comp crashed, upon reboot vid card fan spins full speed constantly(which it used to do for 1sec then slowed down on working boot),no beeps or picture on screen. mb light still green. vga lights still green. all case/cpu fans spin normally.

first i cleared cmos, swapped rams, tried each stick by itself, no change in status.
initially though vid card, bought galaxy 9500 gt pcie card, tried ram swaps again, still no change in status.
Then i bought new ps; 450w bfg gs series, tried vid card swaps and ram swaps, no change in status.

all that is left to try is CPU, HD, and mb. I cant really tell if HD is working as it should...should it be spinning/making noise on boot if mb or cpu is at fault? how can i test hd without another desktop?

It sounds like mb now to me. Can i please get some other opinions before buying a new board?
Thanks in advance.

 

[Devilpapaya]

Sounds like Mobo to me as well. If you are not even getting a POST there is little to no chance that the HDD is causing the problem.

You can try unplugging the HDD and booting. The computer would still POST normally up until you got a "no bootable devices" error.

As for MoBo vs. CPU I tend to hear that MoBo fails more often than the CPU, but don't quote me on that. You can try an identical MoBo with the same CPU and see what happens, but no guarantees.

 

[Soccer4Don]

Since you are not sure where to start did you just recently add the GPU? Do you have a onboard GPU? Since you said something about it maybe there is something wrong with your PCI-e slot. try and plug into (either the onboard or your other option for a GPU) and see if you get something on the screen.

 

[ZXT]

HD is the last culprit here as PC's will still post even without an HD. You are right, it must be the Mobo.

 

[RebateMonger]

As for MoBo vs. CPU I tend to hear that MoBo fails more often than the CPU, but don't quote me on that.

I'm not saying that CPUs never fail, but I've been troubleshooting PCs for 25 years now and I've NEVER seen a failed Intel CPU.

 

[ZXT]

I'm not saying that CPUs never fail, but I've been troubleshooting PCs for 25 years now and I've NEVER seen a failed Intel CPU.

Been trouble shooting PC's and I''ve never seen a failed AMD too...back in the days of K6

 

[Patrick Wolf]

Maybe it needs a new BIOS battery? lol /shrug

 

[mbevolution]

unplug ur psu, then press on button and hold it for a while, then plug everything back together and start again see if it solves the problem, if not, try resetting cmos, if still no luck, then plann to get a new mb.

 

[Matt1970]

I'm not saying that CPUs never fail, but I've been troubleshooting PCs for 25 years now and I've NEVER seen a failed Intel CPU.

The last failed Intel I saw was a 486 and the last failed AMD was a 2400+.