So i have this keyboard,a marvo km400. I was playing games today and suddenly noticed the M key, N key and th Fn key is not working. So thinking it was dust, i opened the keyboard and basically did nothing more than taking photos and blowing some dust of (ps. There was almost no dust on the membrane of the keyboard). So i put it back together and tried to turn it on but this time a lot of keys are not working?!! I resetted and reinstalled the HID keyboard drivers but to no avail. This keyboard is very dear to me. So BUYING ANOTHER IS NOT AN OPTION. I have attached photos of the circuit and membrane. I have basic soldering and electrical knowledge (hobbyist) so keep that in mind.
TL;DR.. Keys suddenly stopped working, more keys not working after disassembly-reassembly, How do i fix it?