Z270-Gaming-K3 boot loop

[GTXPlayer]

Hey, I have had a problem with my build for a while now and I don't understand the cause.

The problem is this: Sometimes (very rare occasions) my computer will boot for around half a second, then immediately shut off. It happened to me this morning and previously I couldn't find a way to "fix" the issue. The mobo would just eventually work with time (usually would take around an hour). However, when it happened today, I decided to unplug the CPU power connectors and let it attempt booting. It lasted around 10 seconds and then shut off. I then put the power connectors back into the CPU slot and the PC booted fine after that.

At first I thought it was overheating problems, but this has happened multiple times on first boot in the morning, when I haven't touched the PC in 10+ hours.

Update: It happened again this morning and taking out the CPU power socket did not work this time around, but switching the RAM sticks around their slots (I have 2 sticks with an empty slot between them) seems to have worked....

So, does anyone know what the cause could be?

I hope you can help. Thanks

[shadowsports]

Greetings,
Helpful description, but not enough information to go on.  Can you confirm your RAM is on the QVL for your board? 

What are your complete system specs?
Did the system ever work without issues?
What BIOS rev are you using?
Have you flashed to a newer BIOS recently?
Have you tried CLR_CMOS and testing start up?

Bench testing usually involves removing all installed components from the board, except CPU, fan and a stick of RAM.  Sometimes its even necessary to remove the board from the case.

If possible, you should try to test the components individually.  Swap a PSU, test RAM using memtest, etc.  I'd start with clearing the CMOS and working from there.