Motherboard or something else

[taub9]

I'll start by presenting my Pc:

Antec 900 case (quite dusty)
Antec Truepower Trio 550W PSU
Asustek M2N-E (AM2) motherboard
AMD X3 440 (AM3 CPU supported with latest beta bios, flashed with EZflash some 4-5 months ago without hiccups, replaced an X2 4400+)
Scythe Katana CPU cooler
ATI 4850 video card (basic Sapphire card, replaced an aging 7600GS, the same time I did the CPU upgrade)
3 HDDs (250Gb/750Gb/1Tb)
4 DIMMs DDR2 800 Corsair totalling 4Gb (2x512,1x1Gb,1x2Gb)
only back and top fan of the case connected to the PSU due to it being such a dust magnet as well as pretty good temps.
basic Samsung DVD-RW
no floppy

Started the PC in the morning, left for work, wife turned it off before her leaving for work a bit later, without reporting anything suspicious. I come home try to turn it on and it won't post. Leds light on, HDDs seem to be working fine, all the fans that should be working work, when I connect an LED lamp to the USB port it works as well.
Screen (LG 1970HR) stays black, as in sleep mode. Clearing the CMOS didn't do anything (not that I expected it to), going back to the 7600GS didn't do anything either (same behavior).

What I can do is:
- read the tensions on the power supply with a multimeter I'll have to borrow although that might not mean anything (tensions can be all fine, still doesn't mean the PSU will deliver enough power to the mobo)
- do the whole one ram, no hdd, no peripherals thing see if it posts (I was to tired last night to try that)
- test the screen on my laptop (though highly unlikely, if it was the screen I should hear the OS starting up in my speakers)
- change the motherboard battery (it has 4 years as does the motherboard and the power supply)

What I can't do (without buying new):
-change power supply
-change motherboard

Basically none of my friends here have any comparable desktop machines as most use laptops

I could also take it to have it serviced although after seeing some worrying TV reports I'm not that eager to try that, also if it's the motherboard having some technician tell me what I already suspect might cost me almost half the price of a new motherboard/power supply

Does anyone have any other ideas of how to go about this problem or maybe went through a similar experience ?

 

[fffblackmage]

It sounded like the computer booted, but you're just not getting any video. You don't have another monitor to test with?

 

[mfenn]

"By HDDs seem to be working fine", do you mean that the HDD activity light flashes and/or you hear them crunching? If so, you've probably got a problem with the monitor (since you tried changing GPUs).

 

[taub9]

Hi, it's not the monitor I have tested it yesterday. As already mentioned the PC doesn't post, it doesn't get to the bios screen.

I carried out some further testing:

- monitor works well on my laptop, monitor cable works well
- tried to see if it gets to the bios screen with one ram,videocard and cpu obviously, with and without hdd, everything else disconnected but nothing changed
-put in new cmos battery just to be sure, again no change
-checked the PSU volatages on the main rail everything is as it should 3.28 for 3.3, 4.99 for 5 and 11.98 for 12V (with a cheap supermarket multimeter i'd say it's within specs), of course one way to know for sure would be to test with a new power supply but as mentioned I have none available (unless I buy one)

Frankly i don't see much hope in it. I'm amazed that a motherboard would die like that, all of a sudden, without any hint beforehand, without any trace or smell of something burned and after 4 years of being stable and reliable (I know it's not the norm for the M2N-E's for which I also found a rather unflattering thread on anandtech forums but that seemed to be mostly because it would limit OC by limiting memory voltage to 1.95).

If anyone has any ideas on how to further troubleshoot the motherboard I'd appreciate it. I would like to at least know what went wrong before taking it out for good.

 

[mfenn]

So what did you mean when you said, "HDDs seem to be working fine"? A failed (i.e. won't spin up) HDD shouldn't cause the machine to not POST.