DVD disc tray will not open

Without knowing the model for the unit, it makes it a little difficult to troubleshoot, but usually the easiest way to get one of these to open up is to try resetting them. This is done on MOST DVD players by unplugging them for about 30 seconds while you hold the power button down to discharge any power that might be held in the unit, then plugging the unit back in and trying to eject it again. Keep in mind, that if the unit was moved (or even if something caused the unit to shift, like a person jumping near it) then the problem could be the dvd has become dislodged from the tray. Many dvd players will have a small hole on the front (usually below the tray) where if you insert a paper clip in about a half inch, will eject the tray part way, and then you can gently pull it out the rest of the way (making sure you do not keep pulling if you feel resistence as the dvd might have skipped out of the tray track). IF worse comes to worse and you don't have a warrenty on the unit, many dvd players can be opened by removing 1-2 screws from the left and right sides, and possibly 1-4 screws from the back of the unit (look around the edges, the screws near the ports on the back usually holds those ports in place and do not need to be removed to take the case off). Once the screws are removed you would pull back and up on the case to open the dvd player. Keep in mind, this voids a MFG warranty. Once the case is off you should be able to see the dvd and remove it unless you have a cheap dvd player which has an enclosed drive. Remove the dvd and with the case still off, plug the power in (DO NOT TOUCH ANYTHING INSIDE WHILE THE POWER IS PLUGGED IN) and try hitting the eject button on the front. IF it ejects now, you should be good to go, just put the case back on. IF it doesn't eject, then your motor is probably bad (or something is blocking the track) and it is usually safer/easier at this point to just go buy a new dvd drive.