pc not booting

[aFeect]

So, all settings are stock, except xmp is on and I've tested with off and on, same shit, it worked for ~ a month or two perfectly fine after building, but suddenly when I turn off my pc now and then the next time I want to turn it on my GPU fans start spinning @ 100% and I have a black screen that says display port no signal and pc isn't booting. It boots perfectly if I shut down power supply and then turn it on again then there's no problem, so what's the issue, how can I fix this anyone know maybe? Bios version is 0906, I updated it from version 06** something something can't remember.

Here are the specs:

MB: Asus Strix Z270H

CPU: i7 7700K /w hyper 212 evo

RAM: Corsair Vengeance lpx 16GB 3000mhz

GPU: Asus Strix GTX 960

PSU: Corsair RMx 650W

SSD: Samsung 850 evo 500gb

HDD: WD Black 500gb

CASE: NZXT h440

[BritishTechGuy]

Probably seems pretty obvious and you have probs. already done this, but try unplugging and plugging all the internal and external cables back in.

[aFeect]

That didn't help, I've tried unplugging every cable and removing ram, graphics card, but the issue is still there.