I recently upgraded the CPU on my prebuilt PC (bought 4 years ago) to an AMD Ryzen 7 5800x. Applied enough thermal paste, properly screwed it in, yet when I hook everything up my monitor says no signal. Tried reinstalling the small circular battery inside, cleaned my RAM and GPU, didn’t see anything loose within my pc. I can start my pc and everything spins to life, yet my monitor says “no signal” and proceeds to black screen.