I've got a Sony CMT EP707 cd-player:
http://esupport.sony.com/US/perl/mod...07&region_id=1

....which a friend asked if I could fix. The problem was that the tray
was sticking out, and wouldn't go back in using the buttons provided.
So I opened it up, got the tray working again, but I don't know how to
configure the 3-plastic disc 'holders' (and I think they might have
been the reason the tray got stuck). Does anyone have any diagnostic
steps I should take? I've only ever fixed my car cd player (which just
required some superglue under the gears)

I'm greeted with combinations of CD ERR 1 and CD ERR 4. Sometimes the
tray doesn't go back in. Sometimes the round metal thing that locks the
cd in place on top of the laser is in the closed position when it
should be in the open position.

Here's some pictures of the player (taken with my crappy phone, sorry)

http://img224.imageshack.us/img224/3...0704511rh7.jpg
http://img225.imageshack.us/img225/7...0704512ac0.jpg
http://img151.imageshack.us/img151/8...0704513nu7.jpg
http://img151.imageshack.us/img151/6...0704521tj7.jpg
http://img172.imageshack.us/img172/6...0704522xd0.jpg
http://img172.imageshack.us/img172/9...0704531ne4.jpg

The 'holder'
http://img172.imageshack.us/img172/6...0704541sn5.jpg
http://img441.imageshack.us/img441/1...0704542vo5.jpg

So if anyone knows how to fix this particular model or generic
troubleshooting steps with this type of changer, please help!