pc only shows black screen

[Netzup]

Hello Guys

 

My computer won't show anything but a black screen. At the start, I thought it might be a bad disk, but I've replaced the disk with a spare SSD and it hasn't changed a thing. I've created a boot drive (USB) with Rufus (tested it on another pc) but when I try to boot to the USB-drive from BIOS it either freezes at the windows flag or the screen remain black. 
I've followed almost every step in the guide below,  besides changing to another PSU or replacing actual parts. I don't have any compatible with my mainboard. Then I found my old  Power On Self Test card, hooked it up chose AMI BIOS,  and got error code 11:

Pin23,24 of keyboard controller is blocked/unblocked. Going to check to check pressing of <INS>key during power-on.CMOS status register initialized.Going to disable DMA and Interrupt controllers. Going to disable DMA and interrupt controllers. Address line test passed. Address line test passed.

 

I must admit I do not understand the actual meaning of the error code, and I feel kinda confused. Hope you guys know what to do, thanks in advance (;

https://www.lifewire.com/fix-computer-that-turns-on-but-displays-nothing-2624443 

 

Specs =

Mainboard: ASUS Z97-P

CPU Intel I5-4690K

Graphics card: GTX 970

PSU: Cooler Master 600W (RS-600-ACAA-BA)