PC won't turn on - help!

[figo_01]

Hello guys,

(Backstory) Ordered my custom PC from this website on 2015 - has worked flawlessly. 2 weeks ago, I woke up in the middle of the night because my PC was turning on and off by itself. Since I was half asleep, I switched if off from the back and went back to sleep. Came back from work to find that it wasn't switching on - it will power for about 3 seconds before turning off.

What I've tried

I have booted the PC without:
SSD
RAM
GPU
Nothing connected to the USB ports.
The PC will begin booting but after 3 seconds, it'll turn off and attempt to boot again. (No beeps)

Luckily I have an old gaming PC that I was able to use parts from so I:
Connected the old PSU I had to see if it was a power problem - it wasn't. (Same wattage)

I guess I have narrowed it down to the last 2 components. Motherboard and Processor. I don't really want to use the old motherboard and processor - I guess I'm being lazy but also I don't want to just in case something goes wrong.

Has anybody ran into a problem like this before? Any suggestions would be appreciated greatly.

Specs if needed:
Gigabyte z97x g3 LGA1150
i7 - 4970k
GTX 980
2x 250Gb ssd
32gb ram
corsair 650w cs series
corsair h60 series

 

[Scott]

I think you are correct. It could be either though, unfortunately.

All other errors would give you bios beeps/error codes/something.

Re-seating the CPU might suddenly fix it. I've had this sort of issue before when a cooler has been on too tight.