It is actually more like an instant shut off instead of a shutdown.

Motherboard is a gigabyte ep45-ud3p with q9650 cpu.

System will idle all day but as soon as I start doing anything on it, like web browsing, it will die within a few minutes and will not come back on until until it has cooled off.

The system ran fine for several years and only recently began misbehaving.

psensor shows the CPU temp to have maxed at 100 and then stops reporting. The the system dies.

Yes overheating can cause a shutdown.

60 degrees celcius is the max for long periods. That 140 in fahrenheit.
45 to 50 degrees to be on the safe side.

Run this command to find out the temp of your CPU:
You can limit the CPU frequency by overriding the 'scaling max frequency'from commandline.
Look in /usr/lib/systemd/system and there should be a 'cpupower.service'

The cpupower.services uses a configuration file. Follow the instructions in that file and change it to:
#CPUPOWER_START_OPTS="--cpu all frequency -set -governor ondemand -min 119000-max 2666000"
#CPUPOWER_STOP_OPTS="frequency--set -g ondemand"

Than restart

-::- Remember anything with the # sign in front of the string is ignored.-::-

Additional links that can help.
https://wiki.archlinux.org/index.php...quency_scaling
https://wiki.archlinux.org/index.php/S.M.A.R.T.
http://itsfoss.com/reduce-overheating-laptops-linux/

Things get old, electrical resistance goes up. Things pop.

I tend to open the box up and clean it - maybe add fans if you've got room. For this laptop I rip the back off every 6 months to clean it.

Hi...

Have you checked the condition of your CPU heatsink and/or fan? Does the fan work correctly and is the heatsink free of dust, lint and other debris?

Regards...

When the system first started act bad I opened it up and blew out about 700lbs of dust - yes I'm exaggerating. Shame on me for letting it get that bad.

Looks good now but the damage was done.

If this is a desktop system and if the CPU is is damaged, hopefully a replacement (CPU) would fix this problem.

Regards...

If the sensors report high temperatures then its a cooling issue. Re-seat the cooler and re apply the termal paste (clean the previous one). Or buy a new cooler.

sharky,

I think that you have probably cooked your CPU.
You may well be looking at a new CPU, motherboard and memory.

The Intel Pentium Dual Core G3258 3.2GHz Socket 1150 is benchmarked at 3996.

The Intel i3-4160 Socket 1150 is rated at 5037, but is far more expensive.

Have you checked the cooler fan? Dust can cause the bearings to disintegrate, it looks like the fan's turning OK but if you spin it with the power off it wobbles. Replace it and make sure the CPU heatsink fins have been completely cleared of dust and fluff. You may get a few more miles from your system as you say it works after cooling down but your CPU is now heat stressed...

beachboy2's solution may be the long term one.

Play Bonny!

Bingo!

First the cooling fan would hardly move manually with the system turned off. There was large clump of dust stuck between the fan and the heat sink. It was a thick heavy clump that didn't get blown out from my previous cleaning. I pulled that out and the fan moved freely.

However, after powering up the system the fan did not start spinning. I gave it a little push and then it began spinning.

I am using the system as I enter this comment and the temp is holding steady around 36 degrees C.

Now I have another issue. I will probably replace the heat sink and fan but I can figure out how to get it out. The fan is attached via four 'legs' that snap into hole in the motherboard. I can't figure out how do get them to release without breaking something.

Cheers,

This is actually normal with the GA-EP45-UD3 series, the fan will start spinning once the CPU reaches a certain temperature. Nice system that you have, I had a quite similar one (non-P version of the motherboard, Q9550), overclocked like hell with a good cooler, could easily reach 3.8GHz stable with a Scythe Mugen II.

Check page 15 of the Motherboard user manual which tells you how to fit the cooler, the reverse is also possible.

Step 2 tells you how to rotate the top of the male push-pin to remove the cooler. Otherwise you'd probably have to use something like a small screwdriver to push the push-pin(s) back through the nylon latching mechanism (see step 5 on page 15)and you should be able to remove the cooler if the "official" method doesn't work.

Now... Finding a compatible replacement cooler could be much more fun!

Play Bonny!

I was mistaken about the fan starting up on it's on. Turns out there is a delay of a few seconds before it starts. System is running just fine now.

This has been educational for me.

Thanks to all for the comments and advice.

You're welcome, glad your system is working well now.

Regards...