Multiple BSOD, Multiple errors

Since before my warranty expired I've been having a problem with my R5. It keeps blue screening and dying on me. A tech came out and replaced the Ram which he said would fix it, but it has not. I've since gotten multiple BSoD, and each time I am getting a completely different error. The last ten shown have been:

Critical Structure Corruption

Memory Management

Cache Manager

KMode Exception not handled

Bad Pool Caller

Critical Structure Corruption

Memory Management

System Service Exception

Bad Pool Holder

Kernal Security Check Failure

These have occurred with the computer freshly started up and nothing open, with games open, with Chrome open, and with multiple things open. As far as I can tell there's no pattern. The computer is also stuck wanting to update every single time I boot up. It goes to a green screen and says it's updating, claims to be done updating, and starts. Then it does the same thing next time I start it up. 

I really need help here as I've run out of ideas. I took it in to get it looked at but they did nothing.