PC Crashes and won't start up again

[rollercoaster12]

Hello everyone,

I built my PC back in December of 2015 with the following parts:

Motherboard: GIGABYTE Intel GA-Z170X-UD5
CPU: Intel i5-6600K Skylake 6M Quad-Core 3.5Ghz (I had it overclocked at one point, but it is now back to the factory setting)
GPU: Gigabyte GeForce GTX 980
RAM: 2 x 8 Crucial Ballistic Sport 8GB 288-Pin DDR4
PSU: Corsair AXi 760W

For a long time it ran perfectly; no crashes, nothing that was bothersome. Around April my computer began to crash 15 minutes or so after starting up and it would enter this strange startup loop where it would begin to power up and then crash again. I recorded several iterations here:

https://www.youtube.com/watch?v=hvnvn-bNy68&feature=youtu.be

The only way to stop this loop is to physically turn off my power supply. The power button on my case and on my motherboard don't seem to do anything. Even after I turned the power supply on and off, if I try and start it up my computer just goes into the same loop. So I sought out help and people told me it was a ram issue, and that I was running 2400MHz ram instead of the recommended 2133MHz ram. I bought a (only 1) stick of this ram to replace both old sticks:

https://www.amazon.com/Kingston-Technology-HyperX-Internal-HX421C14FB2/dp/B01D8U27YU/ref=sr_1_3?ie=UTF8&qid=1478442866&sr=8-3&keywords=hyperx+ddr4+8+gb

It worked wonderfully until late October when it began to crash again. The first time it crashed my computer started right back up again, so I assumed it wasn't the same problem. But it occurred more frequently and became harder to get out of the loop. Sometimes if I jostle the computer lightly, it breaks the loop and it starts up again. However, it crashes shortly after. Resetting the CMOS battery has not helped either, I have tried that extensively as well as changing my ram stick to all the different slots. I have also re-checked the cables to make sure they are properly connected, which they are.

This crashing loop occurs under any circumstance, whether it be sitting idle at the start screen or in a game. I would really appreciate it if someone would help me fix my computer, this bug is really bothering me. Thanks!

[autotech]

Take all parts out of the computer case and build on a box. Make sure to take all parts out of motherboard and so on. Build it like you were doing it for the first time and use only what you have to. If you have onboard graphics use them and only 1 stick of ram. Now turn it on if it powers up fine then you know you had a loose part or something is grounding out on case. Let us know how it works out so we can further advise.

[esota]

Do you have the latest BIOS update?