Blu-ray drive not taking in disk's, but it works in another PS4.

Hi,

I have a PS4 that i’m trying to fix, the problem is with the blue-ray drive, it initially appeared to be totally dead, wouldn’t accept a disk and mechanically wouldn’t do anything. Although when i press the eject button but it would beep 3 times and if the system is off and i try to insert a disk the PS4 will boot up. But at no time is there any mechanical activity form the blu-ray drive.

I put swapped a know good drive into this PS4 and the same thing, totally dead, wouldn’t attempt to take in a disk. So i then put the suspected faulty drive in the other good PS4 and sure enough it took disk sin fine read and displayed the game (although of course wouldn’t play as married to other system)

So this means the drive is actually perfectly fine, so i put the drive back in it’s original system and used the data and power cables form the other system to check incase it had bad cables, but still it would not accept a disk.

So now im thinking the issue must be something to do with the mainboard possibly? Im wondering if you clever people here might be able to assist me on where i should be looking? or if anyone has experienced this before and could help me out?

Many thanks in advance!!