half boot unknown & bizarre hardware issue

[FullMetalKerbin]

Ok. Girlfriends computer, not mine. Asking due to incompetence. Okay here we go...

 

...so I hit the power button, and only half of the computer turns on. Back fan lights up, one of two top fans on a radiator come on, 1 of 3 fans on the front come on, Cpu lights up, graphics card lights up, mobo lights up. The screen is left black though.

 

Sometimes, it does decide to work and we only know that because the front two fans that wouldn't work, will light up blue and spin.

 

Now on the occassion that it does the half boot thing, if we leave it on for like 3 hours it might eventually, hopefully, thankfully, fully boot up all the way. Like one thing will come on at a time kinda boot up.

 

Sometimes the mice, keyboard, mousepad lights come on, sometimes they don't.

 

One would assume, power supply. Plugged it into power supply tester, works fine except when you wiggle the 24 pin cable around then it flicks off but that might've been just user error.

 

Another weird thing is that once it is fully booted no matter how violently i shake it, or excessively tap on things it wont shut off. Its only upon start.

 

Put new thermal paste on even though it looked fine from previous owner, now it will only half boot.

 

We were thinking its the 24 pin cable or the 8pin that we think is the psu power cable or it could be the mobo ports for each of those but im not sure on how to test that.

 

Ive never had a computer that would half boot. Its always been either you do or you don't. Any help is appreciated. Thank you for reading my story.

 

Specs that I know:

Cpu: I7 (idk)-k 7400k or 7700k

Gpu: Asus 1070

Ram: Crucial Ballistix 16gb (2x8gb)

Psu: Corsair CX750M

Mobo: asrock fatal1ty z97 killer

[FullMetalKerbin]

Hahaha solved

 

Bent psu pin