Delco Radio Repair

[SS/GN]

I have an original Factory installed cassette that when you put a tape in, it just clicks and goes in the forward or reverse mode and you cant here the tape moving. It will not play and will eject the tape out if you push the eject button. I took it apart and removed the cassette assembly, the belts are fine and not dirty at all ( original low km car ) Any thoughts??
thanks in advance
Kevin