PC force shutsdown under load.

[JMcGlads]

When running Furmark or playing Crysis 3 and Battlefield 4, my PC will force shutdown. The fans spin up to max, usually the sound gets drawn out and there is a long, deep buzz then the computer shutdown. It then attempts to restart but it doesn't post. there's just a black screen. This has only started after updating to windows 8.1. About 4 months ago I added a 2nd GTX 670, approximately a week after a problem developed where the computer would restart a few seconds after I turned it on. This only happened 4 out of 5 times I turned it on. I noticed that when I turned on the PC three red leds would flash in turn on the mobo on booting up. It's a single flash that last for 2-3 seconds. The leds are at the top, next to the cpu and in between 2 PCI-e slots. Now 1 out of 10 times I boot up, it will fail and a blue window will appear telling me to see the advanced repair options or to restart. I've tried to do as much testing as possible before it fails and temperatures are fairly low; CPU @ 40 degrees, GPUs @ 65 -70 degrees. I'm hoping its just a power supply issue.

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My PC specs are: 

Motherboard - P8Z68-V Pro/Gen3

CPU - i5 2550k @4ghz (Was @ 4.7)

Cooler - Corsair H100

RAM - 16 GB Corsair Vengance

GPU - GTX 670 x2

PSU - OCZ ZX 850w (only 2 years old)

SSD - OCZ Vertex 3 120 GB

HDD - WD Black 1 TB

 

[miyabwah]

PSU might be the problem. Also, Furmark is the WORST benchmark software ever.

[TheRoss0411]

I don't trust that PSU

It looked at me funny

[ross06187]

sound like a heat problem, take the overclock off completely and see if it is stable at that.

 

check all the fans are working and that you don't have a dust problem.

 

the first step is to get it stable then start increasing the oc again.