It is a desktop with a slot in the side of the monitor/computer, not a tray. There is a recessed soft sheath with a slit in the center. Even holding one side of the sheath aside with a credit card the gap is too narrow to see anything, and running the credit card a little into the slot I meet no resistance to indicate a "ledge" where there might be a pinhole.

The sounds indicate the cd is trying to eject but is not mechanically able to do so.