Quick overheat on older PC

[Alamosun]

we have an older computer that has recently began to shut down when under the mildest load. (antivirus, video, flash games, sites such as facebook)

the build is
ASUS a8n-sli premium
AMD Athlon 64 X2 Dual Core 4400+ 2.21 ghz
2 gigs corsair
nvidia GeForce 7800GT

It hasnt been overclocked and i never had a heat problem with the stock CPU cooler but recently it just began shutting down under the above situations which to me seemed heat related. I pulled up the ASUS monitoring application and indeed under minor loads such as watching a tv show on the internet, flash game etc...it would show approx a 1 celcius raise.....per second . Pausing the video or antivirus scan, switching internet tabs away from facebook caused the temp to drop approx the same 1 degree celcius a sec. I pulled off the side cover and all fans are running including the CPU fan. I put on a video and let the heat begin to rise, at about 80-85 celcius i carefully felt around the heatsink and pipes on the CPU cooler and noticed nothing but very minor warmth .

Am i correct in assuming this could just be a faulty heat sensor? I know components are all a bit different but could this basically be just a minor fix? It also will shut down when i boot into safe mode.

this is primarily the computer the kids use for internet etc so i hate to invest in a new board and CPU if its an easy remedy.

thanks for any suggestions

 

[Confused Stu]

First a couple of things I'd forget to check, so forgive me for mentioning:

- Have you checked the heat sink on the CPU isn't clogged up with dust? Lots of dust = no airflow = no cooling.
- Have you tried removing, cleaning, re-applying thermal paste and reinstalling the heat sink on the CPU? If your CPU is cooking but your heat sink remains cool then it could have come slightly detached.

It could possibly be a faulty heat sensor, but I think those are built into the CPU (may be wrong here) and an overheating CPU tells itself to shut down rather than the motherboard telling it to. If it is a dodgy sensor then it might well mean a new CPU rather than a new motherboard, but I'd say this is a rare occurance at best so hopefully it won't come to that.

Check the cooling on the CPU is still doing it's job, my money's on a minor problem there causing the issues you're seeing. Good luck.

 

[Alamosun]

Took off the CPU again and although the thermal paste didn't look to bad I removed it and reapplied. Now even running prime95 now it never gets higher than 44c under full load and sits idle at 29c. I guess sometimes it's the little things I've put aside while Im busy overthinking the problem that bites me...thanks for waking me up a little.