Rest the machine by switching the mains off and on, when it comes on and says "wait" press and hold the eject button ON THE MACHINE, this sometimes overides the function the machine is hopelessly trying to do!
I have previously had disks in the machine overnight whilst it trys doing something, and the next day still showing a blank screen I just pulled the plug from the mains (Because not even the on/off switch worked) then referring to the first paragraph, the disk eventually will be ejected with a nice warm temp of 100oC !!!! probably then it will never read the disk again NOR will any PC understand what the machine has done to the disk either, My advice!! if your transferring those treasured memories, make sure the disk finalizes, eject, reinsert, then play to make sure it works before you destroy any original materials!
Steerpike, May 2008