Computer Shuts Down Randomly

[cooktim53]

Ok heres the stats

Video Card:2-Radeon ATI 4400 HD 1Gig Graphics Cards.
Motherboard:Asus P7P55D LE Mother Board
CPU:Intel i7 Processor
8GB-RAM
1TB Hard Drive
PSU is i forget but its a really good one.

So my computer keeps shutting down randomly, I have replaced the Motherboard,CPU, and 1Video card
I replaced the Video Card because it was running at 95Degrees Celsius, the other one is fine its running at 45Degrees Celsius
the CPU is running at 80Degrees Celsius when Idle and when being taxxed, I had that replaced and its still running at the same temperature.

But after replacing almost all the components of the PC its still shutting down, and I dont think its the power supply causing it because there isnt any odd smells or anything coming from it.
And it shuts down for no reason, it could be idling and it will shut down, so I have no idea what to do anymore.

[jason2074]

it could be idling and it will shut down

Could it be that power options are set to choose after specific idle time then shutsdown?

[Allan]

When you say it shuts down, do you mean it powers off?

[Computer_Commando]

...CPU is running at 80Degrees Celsius when Idle and when being taxxed, ...

Temp too high for idle.  Check thermal paste application & cpu fan attachment to cpu.

[JasonC]

i had problems with this too. turned out my cpu was running pretty hot, about 90-100 degrees celcius, so i reapplied the thermal paste.  that took the temperatures down to 40-50 and havent had problems with the temperature since