[SOLVED] Extremely Random Shutdowns

[jawong2000]

My friend's rig restarts without fail after playing any sort of video game for ~30 minutes.

 

Its a prebuilt but he's replaced a lot of the components.

Specs:

Corsair HX850

Gigabyte B85M-HD3

Gigabyte GTX660

i5 4430

16GB Kingston HyperX DDr3

 

So first, he replaced the generic PSU with a Corsair HX850. No luck, same problem.

 

Then he replaced the 8GB generic ram with 16GB Kingston HyperX. Still no dice.

 

Then he replaced the stock cooler with a CM Hyper T4. No luck. 

 

Then he replaced the entire case with a Fractal R5 with 2 intakes 1 exhaust. Still no luck. 

 

Heres the catch. If he leaves the sidepanel off and has a floor fan blowing into it, there are ZERO problems.

 

I've checked all the temps, theres absolutely nothing wrong. GPU hovers ~65 and CPU never exceeds ~50.

 

Please help, much appreciated. 

 

My best guess at this point is that there is something wrong with the board, maybe the power delivery is effed up. The only other explanation is perhaps the GPU is not functioning properly? But then why would blowing a fan help?

[Energycore]

What graphics card?

 

I think it might be some component on the motherboard heating up and causing the protection circuit to shut the computer off

If it was the GPU turning off the computer would keep going but the monitor would stop displaying - that's thermal shutdown

[FeiROG]

what is your mobo temp like? Overheating from the north bridge can cause these issues, I have experienced this in the past. if the mobo temp (north bridge and south bridge) is about 75-80 i would say these odd issues can start to happen. You can try to do a bios flash and/or update the bios, this fixed the issue for myself. 

[jawong2000]

Thanks guys, I too think its most likely the mobo.