Some DVD players have a child lock feature that prevents children from opening the disc tray. In order to disable the child lock, try the following:1 Make sure the child lock feature is disabled. 2 Try to open the disc tray. 3 If the issue still occurs, power off your DVD player. 4 Unplug the power cord for 30 seconds and then plug it back in. 5 Power on your device. 6 Try to open the disc tray.