Computer lock-up issues

[neigenoire]

The issue: PC locks up, no error messages, no BSOD, no warning. Happens completely randomly, even when idle. It's one of those complete freezes where nothing responds - mouse pointer does not move, keyboard led's become frozen, etc. Sometimes it happens multiple times a day, sometimes a week will pass with no lock-ups. There are no performance issues, the BIOS and all drivers are updated to the latest version.

System specs:
Windows 7 Ultimate 64-bit
CPU: AMD FX-4300
RAM: 4.00GB Single-Channel DDR3
MOBO: ASRock N68-VS3 FX
Video: 1024MB ATI AMD Radeon HD 7700
465GB Seagate ST500DM0
PSU: 500W Corsair

Things I've tested:
1. RAM with Windows Memory Diagnostic tool. Returned no errors.
2. HDD with CrystalDiskInfo, reported health status was good.
3. Replaced the PSU with new one, the issue persisted.
4. I've removed most components from the motherboard, cleaned all connections from dust.
4. Formatting and reinstalling Windows does not help.
5. I've checked temperatures, the system is well cooled.
6. None of the capacitors on the motherboard are swollen.

To me all of this points towards a faulty motherboard, although I can be wrong. I currently don't have spare RAM, HDD or GPU to swap out unfortunately.

Any suggestions/tips before I just buy a new motherboard?

 

[neigenoire]

Bump.

 

[Shaun o]

Well you have done a pretty good and thorough test of the system.

So like you, I am inclined to say it`s a physical motherboard fault, or a problem.

Probably some where a bad solder joint on the motherboard, that is dry or cracked.
And is intermittent due to heating and cooling of the motherboard it`s self neigenoire.

If the board is still under warranty, send it back to where you bought it from under the RMA procedure.
Get a new like for like replacement, not much more that you can do but that, since you tested every other thing well enough.

 

[neigenoire]

Yeah, the motherboard is quite old as well, wouldn't be too surprising. It's no longer under warranty, so I guess I'll just order a new one and see what happens.

 

[neigenoire]

Well, here's a late follow-up.

I finally bought a new motherboard, a new hard drive and RAM. Installed a new OS on the new drive, kept the old one connected as storage. Within 7 days I've had 2 freezes. The exact same symptoms.

The only components that haven't been swapped out yet are the CPU and the Video card. I'm really confused now, because a video card going bad wouldn't make the whole system freeze like that, with keyboard LED's freezing etc., would it? And from what I've heard CPU malfunctions are extremely rare, I've torture tested the thing for hours, it performs without a hitch.

I'm seriously confused.

 

[neigenoire]

Bump.

 

[neigenoire]

Bump.

 

[neigenoire]

Bump.

Thinking of trying a different CPU now, any thoughts? Someone suggested it could be a virus on the old HDD, since I never formatted the D partition. Seems unlikely to me, but I'm kinda paranoid at this point.