The usual advice is "Make it smaller."
You don't need the GPU as the i7 has graphics. The motherboard has video ports too.
You don't need more than one stick RAM.
If that doesn't bring it back then remove the case and put the bare min parts on cardboard for testing.
So the problem is the following. I was playing some games on my PC and it just shut down for no reason. Then it started turning on and off by itself for several times and then I shutted it down myself. Then this happens: Once my PC is plugged on the power and while the power supply is on, the PC tries to turn on by itself and then shuts down immediately. Not even for 1 second. I can barely see the led lights turning on and then they are off. I can hear the click that means the PC is turning on but nothing happens. All by itself. This loop happens every 7-8 seconds and it keeps happening unless I remove the cable or turn off the power supply. I have no idea what is this. Pls help
Setup:
i7 7700K 4.2
Asus rog strix Z270E gaming
Titan XP star wars edition
32GB RAM corsair vengeance 3000mhz
Coolermaster 1200W 80 plus platinum

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic