[Help] Missing something

[Turtler]

Motherboard: ASRock B75M

CPU: Intel i5-3350P

RAM: 1xHyperX 4Gb 1866Mhz

PSU: 600W

GPU: XFX R7 260X

Cooler: Cooler Master Hyper 412S

 

1. First motherboard test (Day X)

Did not have CPU, RAM or GPU connected.

2x Fans connected.

Both of the fans worked completely fine without any breaks. They stopped when the PSU was shut down.

 

2. Second motherboard test (Day X+3)

Installed CPU, RAM, GPU.

Applied cooling paste, installed the cooler.

Plugged in an additional fan and then the GPU (+ the monitor).

The system starts for half a second as all of the fans turn on. It goes silent for a little bit and then the loop starts - everything seems to turn on, then the system turns off, turns on, off...

 

3. Additional information

Nothing happened with the system in the three day gap.

The RAM, GPU, PSU and the cooler work completely fine on MSI 970 Gaming motherboard and FX-8350 CPU.

Attempted to reset CMOS. 

Leads to the aforementioned boot loop, nonetheless.

 

Two scenarios in my head:

1. CPU dysfunctional.

2. Mobo dysfunctional.

 

What else might be wrong with the setup?

 

[Turtler]

4. Third Attempt (Day X+4)

Removing all RAM stops the loop. 

Without it I presume I cannot achieve any monitor output?