Today i was doing someones car and had my son who was in mine watching a dvd via the HU (avic d3), as it was cold i turned on the engine and left it running to heat the car up. It was like this for 30-40mins with the fans on number 3.

after 30-40mins my son shouts at me, pointing at the HU the dvd had crashed. I turned the ignition off then on and it said error reading. The stereo and ipod functions still work but not the DVD. It stayed like this for a bit. It cooled down but it still wont play dvds and it now says system malfunction??!?!? i think some of the displays look slightly different compared to normal.

On top of this the buttons on the left no longer light up and the dvd wont eject, but when you press the eject button it beeps to acknowledge you pressed it. However, nothing happens.

Have i killed it, blown a fuse or just got really hot and check it in the morning?

bump - now says "mechanism error"

I have never seen this. You are going to have to remove and inspect all the rear connections very closely as well as attempting the reset procedures. If nothing sticks out on the exterior surgery will be needed. With all the moving parts inside there is no telling what is wrong.

yeah there is place near by that can fix it for a few ££'s. Am guessing it overheated?