So I have some horrible news guys. I have ordered an empty M4800 LA-9772P for 15 Euro (no CPU, GPU, RAM, storage, screen).
I moved all of those things from my main machine, and installed some eDP screen from Lenovo for now. Because the new frame was untouched and wasn't worn in - that custom GPU heatsink from cicichen went in very snuggly, which I should l have noticed straight away. It tore a ceramic capacitor out of a T1000. Another pin from i7 4980HQ went missing, I guess it stayed in my old motherboard's socket. Laptop tries to boot into windows but fails, it had a WHEA BSOD before. I tried to salvage some pins from an old Socket M Pentium and now it goes to the login screen and shuts down.