BluRay drive not accepting disks.

So I have had this BluRay drive that wasn't accepting disks, so I managed to buy another one and this one is having the same problems... Won't allow the insert of a disk, the motor to insert/eject the disks won't power up... Before I tell the people who sold it to me that it is defective, I was wondering if it is possible that it is the PS3 Mobo... Any suggestions?
I have a CECH-2501b PS3 and the BluRay drive model is KEM-450EAA.