I recently had one that would not post to video, so all functions were useless.  Eject key, no go.  Power on while left clicking mouse, no go.  Command and E, no go.  No OS and no post so using Disk Utility or a command line, no go.  Since I didn’t want to take the entire machine apart I leaned it to its side, pushed a piece of cardboard in the slot to stop the disk from spinning and then pushed Command E, popped right on out.  Thank God for cardboard.