I know it sounds simple, but it might just be the eject button that has been pressed a little too hard. Causing it to be stuck and thus constantly pressing against the actual button that’s attached to the green circuit board with the tiny ribbon cable.
That constant pressing on the circuit board button might be causing the constant eject sounds the console is making.
To check if that could be the problem, remove the bottom panel, and connect your ps4 to power, and to your tv; optional. Then feed it the disk, if it takes it, it’s most likely is that button that is jammed in there.
What I did, was 1.) carefully remove the button from the bottom panel, 2.) put the ps4 back together and then 3.) add the button to the console; carefully, you don’t want to jam it back in there, just push in enough so that it touches the circuit board button.
That worked for me. I spend a couple hours checking the Disk Drive, rollers, the circuit board with the 2 switches, sometimes its just the simple things.
Live long and prosper.