This is a DVR-110D, but you can undoubtedly do something similar with with most drives, especially it's Pioneer relatives. LED's are mounted inside the drive - there are of course constraints to be met here: We must not foil the mechanical components of the drive, eg. the tray, and the light must go somewhere where we want it, e.g. out the front. In this case, the top and bottom parts of the metal casing are removed from the plastic chassis, and a rectangular section cut out from the back of the upper steel casing, above where the rear connectors are. Two holes are drilled in the black plastic chassis, and LED's inserted. The anodes of the LED's are connected to +5V on the main PCB via appropriate resistors. Now here's the tricky bit. One of the pins on the tray limit switch is grounded only when the tray is fully extended, so the cathodes are connected to that. I'd show you specifically how it's wired up, but i can't be bothered removing and disassambling the drive right now. Works as planned - the LEDs illuminate only when the tray has fully opened, and turn off immediately when the tray starts to close.