Broken ribbon connector between bd-rom and motherboard. Try flipping it before ordering a new one. It worked for me. I believe the issue affects people who have opened their ps4 for cleaning or fixing another issue. When removing the ribbon cable connecting the bd-rom to the motherboard they broke the left pin on bd-rom slot. By flipping it, it might bypass the issue. I also updated using a USB stick so I didn't have to download every time I tried another fix. Also used the 1 gig version of the update;not sure if that made any difference. Good luck.