If for some reason you would opt for user performed action, then pls try:
1. reset, unplug from the mains for at least an hour and try again;
2. check if there is a slide switch of some sort at the rear of the unit;
3. check if there may be a pinhole somewhere along the bottom of the loading tray where a blunted point safety pin maybe inserted;
4. open the top cover and manually eject the tray;
5. check internally if there is a mechanical problem such as a slipping/cut belt, gears that do not mesh correctly;
6. if the unit has been in use for some time, it may simply need cleaning and re-application of lubricant in the mechanical assembly.

The slider mechanism, depending on the age of the unit and , consists of the small chrome rail, a drive motor, a small gear assembly, and (in some units) a small belt that drives the slider unit via the motor. This small belt causes all sorts of problems. If the belt is broken or slipping, it can cause skipping, dropouts, or simply no start up at all. Also, if the belt breaks in the middle of the disc, the drive mechanism gets hair or dirt wrapped up into the gears, or the pick-up assembly doesn’t return to the start position (called home), the unit will (99% of the time) refuse to release the disc, causing it to become stuck inside the unit. There’s a little micro or leaf type switch located at home position that sometimes gets dirty or breaks and, causing this problem also.

Hope this may help;

Regards,
VOTIT

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Isee this is rvery one problem just a bad unit on the cd