System fails to POST - any help much appreciated

[metadaptive]

Hi, so I think I probably know whats screwed with my system but would really, really, appreciate any help or ideas you knowledgeable people could offer me. Please ask if you need more info than supplied.

The Set-up:

AMD Athlon 64 X2 Dual Core 3800+ (Socket 939)
MSI K8N Neo4 Platinum nForce4 Ultra (Socket 939) PCI-Express Motherboard
Corsair 2GB DDR XMS3200C2PT TwinX (2x1GB)
Hitachi Deskstar T7K250 NCQ 250GB SATA HD
Sapphire ATI Radeon X1800 XT 256MB GDDR3
Tagan TG530-U15 530WATX2.01 Easycon SLi Compliant Modular Silent PSU
Arctic Cooling Freezer 64 Pro CPU Cooler

The Problem:

So I can home from work today to find my PC (which I had left switched on for I guess about 10hrs) sitting apparently braindead on my desk. The power light remained on and all fans were running but the system wasn't outputting anything out of the video card and was unresponsive to power off using the power button. Flicking the switch on the PSU off then on after a bit, leads to the same situation, ie it fails to POST - no beeps from the speaker but the MSI diagnostic card I have in displays 4 ominous LEDs that according to the manual corresponds to "the D-LED will hang here if the processor is damaged or not installed properly" uh-oh methinks.

Thing is the rig (while a self build) has been running almost flawlessly stable since april, has not been overclocked for any significant period andwas not at the time the fault developed and was not running hot (i had speedfan running all the time and cpu temp never got above 40 deg C). The only problem/niggle I had with the system was the occasionally grinding loud chipset fan which seems to be a common problem among k8n neo4 owners, and which speedfan was unable to slow down. The development of the fault was not preceeded by any other warning signs such as random crashes etc etc. The only other sin I think I've committed was using the thermal pad that came with my Arctic Cooler rather than artic silver or similar, but I don't see how this would cause this problem with no prior warning signs ...

I'm guessing either my CPU is fried somehow or my mobo is faulty - can any of you kind people shed any light on what it might be/suggest what I should do try and isolate/fix this.

many thanks in advance

tom

 

[Sir Random]

It could be a dead stick of ram. Try booting with just one stick at a time (try each stick in all 4 slots).

On second thought, the fact that the fans were still spinning and mobo powered up, would make me suspect the gfx card. Try booting with a different gfx card, or with the card removed (mobo should give warning beeps)

 

[metadaptive]

Hi Sir Random,

Thanks for your reply.

I tried both your suggestions - removing the gfx card and trying with just each stick of ram without the other but no joy unfortunately - mobo didn't even beep at the abscence of the gfx card (case speaker definitely works or did very recently), suggesting i guess that things are failing before it even gets to that point.

any other ideas about what it might be?

many thanks again

Tom