PC suddenly shuts down and won't POST

[Cxiont]

Hi all,

PC shuts down suddenly(no warning etc) while gaming a few days back with a PC i built myself about 6 months ago, it's working out fine until recently.

Here is my spec;
p8z77-v ASUS
i5-3570k
GSkill F3-12800CL9D-8GBXL x2
Nvidia 670 gigabyte
Corshair HX750
Thermalight SB-E extreme
CM-HFAX casing

The Dram led lighted up after the shutdown and won't post, fans spinning.
So i reseated the RAM and used the MemOk function, it boots and starts windows normally, but the same thing happened after a few minutes of gaming.
I've done the same process again, it started fine but same thing happened, except this time my pc was frozen.

I've suspect incompactibility of RAM, but it has been working fine for the past 6months, could there be possibility that other parts went faulty?
Please know if any other information is required.

Thanks in advance for helping!

 

[Akashdeep]

Your problem isn't related to your motherboard.

I would recommend you to ensure your heatsink(the thermal paste on your cpu is fine or not. Clean the old heatsink and apply new. I should work fine.

 

[Cxiont]

did that and ran prime95 while monitoring the temperature, the app runs for like 30seconds before my pc shut down again, and the temperature was at 40~45C.
sometimes will even get frozen in BIOS config.. i'm really lost with this =(

 

[Akashdeep]

Are you overclocking ? If you are overclocking then try setting it OFF>

 

[Cxiont]

hmm nope, in the BIOS setting i set it with default setting, and optimized for normal.
however, sometimes after the shutdown, and rebooting (had to do MemOk again), it wrote "Overclocking failed!"
when i first built the pc i'm sure not overclocking was done.

 

[Akashdeep]

Ha?
Your bios is set to overclocking(so it displays error "Overclocking failed!"). Set if OFF and try.

 

[Cxiont]

sorry, new to PC building, where is the option for turning the OC off in bios?

 

[Akashdeep]

Set your Boas setting as EZ mode.

 

[Cxiont]

i went to BIOS, on EZ mode, reset to default.
still the same thing, running prime95 will freeze pc and temperature is below 50C

 

[Akashdeep]

If you don't run Prime95, then what happens?

 

[Cxiont]

i'm using prime95 to stress test my pc in its current state. Due to the fact that gaming in ~10mins will shutdown/freeze my pc, running prime95 will know whether my pc is working fine or not, if my pc could not run a blend test for a full minute atm then it wouldn't handle any games. Correct me if i'm using it incorrectly.
I'm not overclocking my pc at all, in my BIOS i used default settings, using just EZ mode GUI, with balanced mode. It worked fine for 6months until recently it shuts down suddenly and i have this issue. I'm not sure of how the message "Overclocking failed!" appeared.

 

[Akashdeep]

"Overclocking failed" occurs only, if your bios is set to overclocked mode.

 

[Cxiont]

right... thanks for helping...

 

[Akashdeep]

right... thanks for helping...

Please check, whether this can guide you-> http://rog.asus.com/129672012/maximus-motherboards/asus-z77-motherboard-uefi-bios-tuning-guide/