Diagnosing intermittent mobo(?) problem

I knew my easy build was too good to be true!

I'm having this really weird problem that I've never experienced before. Tonight I was playing Skyrim like I have been since I finished the build yesterday, then with absolutely no warning, my computer shuts down, as if the power cord had been yanked.

So I tried to isolate the problem. I switched power cords to the one that actually came with the PSU (thicker gauge), and plugged cord straight into the wall and not into my power strip.

That didn't seem to help as I get random shut-downs and reboots. And usually it will try to start 3-4 times and reboot before it finally gets to the desktop. Even then it will sit there for a couple minutes and the just TURN OFF.

I put this in this section because I think that the motherboard might be the cause. It's really the only thing that makes sense to me. After this problem manifested, the on-mobo power and reset switches started not to be constantly lit, also the digital readout on the mobo sometimes doesn't appear.

I followed the advice of some random thread at TT and reseated the cpu with a new application of TIM (though my old one didn't seem too bad). And still, same problem.

Does anyone have any ideas on a possible cause?

Sounds like thermal shutdown... Have you been monitoring your temps with coretemp under a stress test like Prime95?

Did you overclock the system?

Yup, I've been watching them. Did initial stability testing. 69 or 70 under IBT, 61 under Prime95, zero problems. Now I get random crashes all the time, even at idle.

EDIT: Also I'm at 4.5Ghz

Create a bootable CD for memtest86 and see how it does....

I would, but the computer wont boot, like nothing. Maybe 1 out of 20 times it'll get to the bios and 1 out of 30 times it'll get to the desktop, but then it just turns off and goes into its funny boot loop. I was going to try memtest before, but it wont even stay on long enough to try...

OK, pull your power cord, then pop out the CMOS battery for 30sec to clear everything out. Try to boot to BIOS after that...

You should check your power supply too. You have a good PSU so I doubt it, but it is possible... Do you have a DMM or a PSU tester?

That's one of the things i tried. Didn't remove the battery but used the jumper to clear it. That actually gave promising results. Each time after I did it the computer would get to the bios, and stay for may a minute, and then reboot.

I don't have a DMM, but I have a friend that has one. What would I be looking for?

Borrow a power supply and test with it.

RGone said:

Borrow a power supply and test with it.

Click to expand...

Unfortunately I don't know anyone with another PSU.

But, if I hooked up my VX450 without my 560ti, it should be able to handle the load right?

checkeredhat09 said:

Unfortunately I don't know anyone with another PSU.

But, if I hooked up my VX450 without my 560ti, it should be able to handle the load right?

Click to expand...

Likely if there are not too many fans or hdds or Optical drives to have to supply power to. Of course you do not have to hook up all those to test.

And the plot thickens...tried hooking up system with vx450. Perfect boot. Debug LED working, system started up first time, now running IBT on Very High for 60 loops.

And the plot thickens again. After about 10 minutes of IBT with temps around 66C according to coretemp, the system had another unexpected shut down. Just black screened. Can this safely rule out the PSU as the cause?

checkeredhat09 said:

And the plot thickens again. After about 10 minutes of IBT with temps around 66C according to coretemp, the system had another unexpected shut down. Just black screened. Can this safely rule out the PSU as the cause?

Click to expand...

Most certainly NOT. With other power supply you had gotten to the point where you could not even boot into bios and stay there.

Failure in IBT can be poor stability and even now not enough of "good" power. Which if the last means your original power supply is failing and that is what many electrical components do. They work a little and then quit. Just about the correct time frame for your failure to occur.

But then what does that mean for the PSU I just used? I've been using that for years with zero problems. Wouldn't a similar problem indicate a common component between the two setups. Also, remember I was able to get to the desktop sometimes with the original PSU, just not often.

But then what does that mean for the PSU I just used? = Not enough power for the new board in use.

Wouldn't a similar problem indicate a common component between the two setups. = Sure it could and so far it seems power supply related. One too weak and the other now failing with results that it can no longer even stay booted to get into bios without reboot.

Also, remember I was able to get to the desktop sometimes with the original PSU, just not often. = Yes you did, but now you say you cannot even stay in the bios.

Take three sticks of ram out and see if you can boot better with either power supply. Leave the one stick in the primary slot that is according to the motherboard manual.

Took out three sticks, cleared cmos, and nothing. For both PSUs