If it's a red label drive, make sure you're using a cable with a yellow stripe. If it's black, then it uses the red stripe cable.
That said, it sounds like you need to adjust the zero track sensor to get the drive to read a disk. When you do this, place something between the drive's board and the chassis, since you'll likely fry the eject motor circuit if the board touches the chassis. BTDT when testing out my old Plus and getting it to read disks.