My deck won't accept cd's! and I don't know why!?

so I have a Sony CDX-4000X CD Player Xplod, and it won't accept a cd, the cd will go in half way like it is going to accept in but then the deck like clenches it and makes a grinding noise and I have to pull the cd out, I tried pushing the Rest button and it worked once but as soon as I ejected the cd it only poped out a little bit and I had to grab it with needle nose, and then it wouldn't accept any cd's Even when i pushed the reset button! please help!!!!