Z97X-Gaming 3 stuck in bootloop after a week of performing perfectly

[tanpi]

So I bought the Z97X-Gaming 3 motherboard recently, along with a Core i5 4960K and grandis cooling. I've assembled the whole setup:

Z97X-Gaming 3
i5 4960K
4x2GB Kingston HyperX RAM
GTX 770

And it worked perfectly for around two weeks, the CPU went to 4.5Ghz @ 1.25V stable, around 80 degrees celcius. Suddenly on sunday morning, when I turned the PC on it got stuck, black screen (no signal) and did nothing. After a couple of resets, it cleared CMOS and booted up, so I figured I'll update the BIOS just in case. After restarting it again it got stuck on nothing again. Then I started pinning the faulty component, and it turns out when I took the RAM out it went into a bootloop. Thing starts, and immediately restarts after 5 seconds. No beeps, no flashing diodes, no signal. So I took out everything, even the CPU. The motherboard is still in an infinite bootloop, but without the CPU the light on the left doesn't turn on. With the CPU the lighting comes on but the setup still enters a bootloop. Can't clear CMOS, can't do anything. The keyboard lights won't come on, so no keyboard input.

Anyone got any idea what's wrong? All of the parts worked flawlessly for around two weeks, and also the GPU was in my previous setup, and the RAM is a couple years old with no failures.

Can this possibly be a PSU failure? Or maybe I should just return the motherboard?

[fonyat]

I´m experiencing the same thing with an almost identical system, did you managed to fix it?

Here is my original post, hope you don`t mind:

Hi folks,
I got a ticket at Gigabyte Brasil, but due to a possible delay for the holidays and the fact that my warranty expired (2 weeks before this issue :/), I decided to try my luck here and maybe get a feedback.

After 1 year (and 2 weeks!) working perfectly, my gaming pc started to fail a few boots, taking 2-3 tries before booting. Once started everything was fine and I could play for hours without a problem.
A few days later the problem escalated to this boot loop, where everything lights up (fans, drives, leds) and shuts down 5-10 seconds later, after 2 more seconds the cycle starts again.

My specs (never overclocked):
Proc: I5-4690K
MB: GA-Z97X-Gaming 3 (Rev. 1.0 - BIOS F7)
RAM: Corsair Vengeance 1600Mhz 2x8Gb
VGA: EVGA GTX 970 SC
HD: WD Black 2Tb
SSD: Samsung 850 EVO 250Gb
CPU Cooler: Cooler Master 212x
PSU: EVGA SuperNova B2 750w

What I´ve already tried:
- Taking everything off the case, and testing it bareboned, only PSU, CPU, cooler and 1 stick of RAM (tried all 4 slots)... boot loop
- Same thing with no RAM... beeps then reboot
- Swapping parts with my HTPC (LGA 1155), tested everything except the CPU and motherboard... the parts from my gaming PC worked perfectly on the HTPC
- Took everything apart, cleaned, reaplied the thermal paste, reseated the RAM, CPU and power cables several times
- Carefully searched for scratches, bent pins, blown caps or any sign of damage
- Since the CM 212x have a backplate, I decided to go back to the stock cooler
- Cleared the CMOS by jumper and battery removal
- Tried to force a BIOS restore from the backup chip

After a couple of days fiddling with it I´m completely out of ideas and about to order another motherboard. :/

Any help would be much apreciated...

[Elsie]

And it worked perfectly for around two weeks, the CPU went to 4.5Ghz @ 1.25V stable, around 80 degrees celcius.

Constantly? That's a lot of heat ...