My PC crashes periodically crashes every 2.5 hours, used to be every 4 (99%) sure it's the CPU

I made a post here and reddit 8 months ago due to my PC crashing periodically every 4ish hours. Since then I have spent $400aud on a highly rated store to diagnose the problems and although they swapped out every part except the CPU, the problem will still occur. I inserted my CPU into my friend's PC and it doesn't crash after 4 hours however after placing it back into my PC it starts crashing every 2.5 hours now as seen through the photos linked as it crashed in memtest, standby or while gaming. Should I risk forking out another ryzen 7 7800x3d? Are there any test that I can do? I have sprayed and wiped the cpu with rubbing alcohol and wiping cloth before application. 

https://www.reddit.com/r/pchelp/comments/1ppqqjz/comment/nuony6h/?context=3