System shuts down abruptly at random

[TwOne]

So, I recently upgraded my system a bit so it could run some games. The CPU ran kinda hot, so I made sure to put on some new thermal paste.

Yesterday night, I was browsing the Web when suddenly my system turned off without warning. I decided to go to bed because it was late anyway.

Today, I was playing a light game (NFS ProStreet) and it shut down again. I tried to boot into the BIOS and noticed a few things. The system temp was at 40C (104F) and the system fan would occasionally read N/A. Then it shut off again. I tried to boot it again and it just refused to.

Specs:

Intel Core2 Quad Q8300 stock with OEM cooler and new unbranded thermal paste (applied following Arctic Silver 5 guide)

Acer MCP73T-AD V1.2

4GB DDR2-800 (two sticks in single channel)

750GB Seagate Barracuda 7200.12

EVGA GeForce GTX 750 Ti 2GB SC

Cooler Master V450 PSU

Corsair Carbide SPEC-03 (only exhaust fan is hooked up, because the motherboard has only one fan hub)

Windows 7 Home Premium 64-bit SP1

Temps under load:

CPU: 70-75C

GPU: 35-40C

[404-USER-NOT-FOUND-ERROR]

did you overclock?  did you spread the paste correctly?

[TwOne]

did you overclock? did you spread the paste correctly?

I have a small overclock on the graphics card. Also, I used Arctic Silver's guide on applying thermal paste on C2Q processors.

[404-USER-NOT-FOUND-ERROR]

I have a small overclock on the graphics card. Also, I used Arctic Silver's guide on applying thermal paste on C2Q processors.

what method did you use? pea, line?

[TwOne]

what method did you use? pea, line?

I used the line method and let the weight of the cooler spread it out.

[404-USER-NOT-FOUND-ERROR]

I used the line method and let the weight of the cooler spread it out.

then that shouldn't be a problem for air pockets, I would try reversing the overclocks and I would check if the thermal paste is around the CPU (maybie u put too much)

[404-USER-NOT-FOUND-ERROR]

also try scanning for viruses with malwerebytes just in case its a virus, maybe you can update BIOS but I wouldn't recommend it since if it shuts down you could damage your computer

you could also check if your RAM and other things are working, just find some software to test

also iff you are running on windows try safe mode

Edited July 26, 2015 by NickLiam123

[Wyre]

You are hitting the thermal limit of the Q8300. Thermal limit of that processor is 71.4ºC.

 

http://ark.intel.com/products/39107/Intel-Core2-Quad-Processor-Q8300-4M-Cache-2_50-GHz-1333-MHz-FSB

[TwOne]

I decided to take the PC outside and blew it out with an air compressor. I made sure to blow the CPU heatsink out from all angles (a lot of dust flew out). When I was done I hooked up the system and these were the temps I'm getting (ambient temp is slightly above 20C/68F): 

 

CPU:

idle on Desktop: 34-39C (93-102F)

under load (max temps): 55-60C (131-140F)

 

GPU:

idle on Desktop: 24C (75F)

under load: 50C (122F)