OK, hopefully someone here can help me figure this out. First of all, here is the hardware of the PC I built.
AMD Phenom II black edition 140W Quad core 3.4 GHz CPU.
4 GB DDR3 1333 RAM (G-Skill)
ASUS M4A78T-E motherboard
300 GB seagate (75% full)
NVidia 9800 GT

Heres my issue. The computer boots up fine and runs great, but at completely random times (could be 5 minutes after booting up or 10 hours after booting up) video output just stops and the computer is non responsive (I try to shut down with keyboard, but nothing), and I have to hit reset button on tower.

What I've tried:
updated drivers: chipset, video, mobo
removed video card and just ran with onboard video.
tried manually entering voltage and timing for RAM
ran RAM test (windows memory diagnostic)
disabling overclock software (seemed to decrease how often problem occurs. I actually thought I had it fixed when I went through a whole day without the issue, but pc froze up the next day )

Anyone have any thoughts? This is kind of driving me crazy

[Edited on January 17, 2010 at 10:03 PM. Reason : .]

1/17/2010 10:02:33 PM

power supply could be the issue

1/18/2010 2:22:43 AM

Really? My ps is 550W

1/18/2010 9:05:44 AM

based on the info you gave and what you've described i would also say power supply. at least that's where i would start my troubleshooting. the reason for that is cause you said once you disable the overclocking the frequency of the lockups occurring seem to decrease. and since overclocking pulls more power from the PSU than normal, there could be an issue there. it's possible the PSU is just a lemon and can't handle the loads, regardless of it being a 550W; there are good 550W PSUs and then there are bad 550W PSUs. if it's not the PSU, then i would next try the motherboard. depending how old the system is, can try to RMA the board. if it's past the RMA period then try contacting Asus support and see what they say. but my bet is on PSU or mobo.

1/18/2010 9:18:21 AM

calling ASUS was the first thing I did. They were telling me my issue is probably with the RAM or CPU. Which is why I tried troubleshooting them 1st.

To update you all on system age:
Brand new: mobo, CPU, and RAM
Everything else: ~ 3-4 years old.

If it was a PS issue, don't you think removing the video card (~100W) would make the problem go away?

The thing with having OC off is yes seemed to decrease frequency of problem, but the issue is so random, that it could be my imagination that is is happening less. It has also run for hours straight with OC on. Also when it does freeze up, its not even doing anything straining (may be surfing web, or has happened when nothing is open, and screensaver is on).

Just this morning, it froze up immediately after booting up twice! booted up fine 3rd time and I've been on it last half hour. This problem is really annoying.

[Edited on January 18, 2010 at 9:40 AM. Reason : .]

1/18/2010 9:38:51 AM

Remove side of case. Point desk fan directly at computer. Test to see if lock ups happen less often.

My money is on overheating GPU or chipset.

1/18/2010 9:56:25 AM

I have noticed to GPU seems pretty toasty to the touch. I'll give the fan idea a try

But I wonder how it could overheat right at boot up sometimes, and then not for hours other times...

[Edited on January 18, 2010 at 10:52 AM. Reason : .]

1/18/2010 10:51:49 AM

UPDATE.

PC has been running last couple of hours. I have noticed PSU is pretty hot to the touch (sensor reading says 43 C (110F). And when I put my nose right up to the back of it (where 1/0 button is) there is a ever so faint burning smell. PC is still running right now.

1/18/2010 10:56:43 AM

Just to let you know...if it runs too hot, some chips on the mother board and graphics card can become so hot they desolder. If that happens...you be fucked. It happens all the time to HP laptops and their graphics cards.

Cool that shit off!

1/18/2010 1:43:27 PM

That bit of burning smell I picked up got me worried a bit. Gonna buy a new psu and see if that fixes it. Thinking I'll go with a 650-750W

1/18/2010 1:57:39 PM

make sure it is a reputable brand and not some brand-x psu. read reviews on newegg and amazon to see what people say about reliability and what not.

1/18/2010 2:16:43 PM

ditto that. Brand matters way more than wattage, though of course there is a minimum wattage that you'll need based on what hardware you're using.

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010090058+50001459&QksAutoSuggestion=&ShowDeactivatedMark=False&Configurator=&Subcategory=58&description=&Ntk=&CFG=&SpeTabStoreType=&srchInDesc=

[Edited on January 18, 2010 at 2:35 PM. Reason : link]

1/18/2010 2:32:48 PM

This has been bulletproof.

1/18/2010 2:37:38 PM

^ best buy has a corsair 650 and 750. I'm gonna check em out and get my buddy to buy me one with him emp discount. The 550w one I have I bought from newegg. Brand is ultra

1/18/2010 4:38:58 PM

couple things:

a) if you overclock, there's a good chance it could just be the cpu dying.
b) if you're computer is still on, just unresponsive, again it makes me think it could be cpu
c) when smelling a PSU, chances are even new PSU's will have a faint smell like burning, it's the smell of electronics, if something is wrong, the smell will be pretty strong
d) if it was the PSU or CPU, changing out the graphics card won't necessarily help, just reducing wattage load doesn't change the result if it's got something wrong with it electronically. reducing load only makes things last longer, it doesn't fix things, although it will help deduce if it's the graphics card problem or not, if you've tried both the graphics card installed and with it removed, then it's not it.
e) try a PSU first as it's the least expensive option and buy a PSU with 80% or higher efficiency, it'll last longer and will give you much better power performance and less likely-hood of flaking out (among other specs, efficiency is a good indicator of quality) corsair=best
f) if all else fails, good chance it's the cpu.

1/18/2010 4:46:40 PM

I really hope it's not the CPU. The thing is brand new!

1/18/2010 5:02:53 PM

.

[Edited on January 18, 2010 at 5:12 PM. Reason : .]

1/18/2010 5:11:29 PM

i hope it's not either. just posting some things to think about. i used to overclock too until i had a cpu die on me, even with adequate cooling, they just don't have the same lifespan (unless you can obtain near stock temps or lower --at least in theory) and things can easily go awry.

let's just assume it's the PSU, for now, until it's proven otherwise

1/18/2010 6:44:50 PM

Was able to run my buddys best buy system diagnostic. CPU checks out and psu is gettin that burning smell that seems to be gettig stronger with time. Whole room has electric scent that my system did not used to produce.

1/18/2010 6:54:51 PM

well then i think you have your answer

1/18/2010 7:04:56 PM

mmm, ozone.

1/18/2010 7:58:45 PM

been running new PSU for last couple hours. ended up going with a 650W Antec. $100, but got it for $70 with emp discount. So far so good. Thanks for the suggestions. I'll be sure to come back if it freezes again.

Anyone wanna buy my ULTRA 550W PSU? it never gave me problems with my less demanding system (2 GB DDR, dual core AMD CPU)

1/18/2010 10:00:42 PM

Quote :

"mmm, ozone."

does a body good!

as for the crapped out Ultra PSU i think it's time to just part ways with it. no one will take a chance on it esp if it's been giving you problems like it has; it may just be on its way out.

1/19/2010 8:11:32 AM

Better than freezing down.

1/19/2010 8:23:17 AM

i don't know why a modern CPU would ever cause the computer to freeze...spontaneously cut off to keep it from burning up, yes, but not freeze (that's old school CPU behavior)

1/19/2010 8:30:21 AM

Install a space heater, usually keeps anything from freezing.

1/19/2010 9:17:02 AM

isn't it odd how we use terms that are contradictory?

PC keeps freezing up because my PSU is overheating.

anyway...glad the PSU was the problem (that I said first)

Actually...I suggested it because back in the day, i built my own computer and was having a similar issue...asked TWW...suggested a PSU and viola! (think it may have been Noen)

1/20/2010 3:28:58 AM

Quote :

"suggested a PSU and viola!"

do you...play it a song to make it feel better?

1/20/2010 8:20:33 AM