Error code CE-35888-2 is a fairly common fault code on PS4 game consoles. Many times it occurs after the optical drive is replaced or repaired. A lot of people think that they can just replace their blu ray drive with another used one from Ebay or somewhere else. Unfortunately this is not the case.
Unfortunately there is no easy fix for this code UNLESS you have the original daughter board that came with your original optical drive (the one that came with your PS4 when it was first purchased from a retailer). This is because the daughter board on the optical drive is "married" to the motherboard. The means that there is a chip on the motherboard that talks to a chip on the daughter board. If they are mismatched they will not be able to talk to each other and that will render the blu ray drive unusable. The PS4 will still play downloaded games but it will not play anything that is loaded into the optical drive.
CE 35888 2 Myths
There is at least one popular Youtube video that "explains" this error code and says that the daughter board needs to have matching numbers to the original board. This is not the case. The numbers on the bottom of the boards only give you a clue as to whether they will interchange with the ribbon cable to the laser in the optical drive. Boards that have an 010 will have a different sized ribbon cable than boards that have a 020 on them. If your original blu ray drive has number 010 and you replace the board with another one that has the same number it will not work because the replacement board is not married to the motherboard.
How to fix this error code
This is the part where I get to tell you the good news. You CAN replace your optical drive! The trick is that you need to find an optical drive that originally had a daughter board with the same number (010 or 020) as the one you have. After you get it all you have to do is remove the board that came with the replacement drive and install the one that came off of the bad optical drive that you are replacing onto the replacement blu ray drive. This way the original board that is married to the motherboard will stay with the motherboard.