**************** FIX (SU-42118-6) *****************
This is for my PlayStation that it worked. I've known I've always had an issue with my Blu-ray Drive. KNOWING THAT i went straight for it when taking it apart. apparently after I changed the thermal paste when i put the BOTTOM cover back on somehow the main (wide flat-pin cable with blue tip and "T" tabs NOT the skinny one with blue tip.) connector for the blu-ray drive came out and the left "T" tab was no longer on the flat pin cable. I used a flashlight looked in the connector and removed the broken off blue "T" tab that would prevent the cable from PHYSICALLY making a connection. Then put the flat pin back in, made sure it stayed connected put back in three screws in the back of the PlayStation 4 for the bottom cover restarted in safe mode option three updated from internet and it actually started to install after the download instead of instantly throwing me the error code of su - 42118 - 6 after downloading.
Hope this works I'm happier than a pig in s***!!!!! if you have any questions post a reply I get updates through email. If I don't respond right away it's cuz I got Call of Duty back LOL