won't open...

Hey this is a great site!
I was having a similar problem with my Toshiba SD-K860. Bobbyj, thanks for the link to the SD-4900 service manual, it was extremely helpful even though it was a different model. I could not find an emergency eject pinhole, and leaving the unit unplugged for a while did not help (two suggestions found on other sites), so I simply took the whole thing apart, got the disc out, found the eject slider on the bottom of the tray, massaged the tray open and closed, and put everything back together again. The connections were solid and the belt was in tact so everything seemed to be fine. Once I reassembled and powered it back up it worked again!
I posted a more detailed solution on my problems to solve site, which is similar to this one:
http://problemstosolve.com/solved/toshiba-sd-k850-wont-eject-solved/

Hi,

try this:-
Power On, then push eject several times, whilst applying a slight pressure to the left and right hand sides of the Drawer.
If the drawer has jammed, i,d suggest using A Blunt Knife ( Butter Knife et,c ) and gently prising the top corners of the drawer, whilst pushing eject/open on the remote or control panel.
If all else fails, dismantle the drive. And remove the disk manually.

Mike @ compurepair.

the door drive belt is most likley broken this belt is on the inside under the door. the part number is 79096669. the service manual is here https://www.vancebaldwin.com/shop/research_new/TBA/SD4900.pdf

I had the same problem with my Toshiba SD 4900. I read these posts, and then decided to take it apart. . I am no expert, but can do some simple repairs. The fix requires taking the top off. I will leave it there since this is an electronic device, risk of shock, etc. etc. I assume if you can take the top off your aware of the risks and what precautions to take, like unplugging it.
Here's what I found, and what I think the problem is:
When you put a DVD in, the tray closes and then the bottom spindle moves up. I think there is an electro magnet on the bottom spindle, because it will pull down this round top (spindle) disc to sandwich the DVD nice and snug. The top spindle is about 1.25" round. Mine was black, and has a little metal piece held in place by 3 little slides.
So, inside this top round spindle is a little metal washer. This is what the bottom spindle magnet will pull on when activated. This washer was highly magetized so even when the electro magnet was turned off, they stayed tighly gripped on the dvd. I think over time it became too magnetic. So, I took the old washer out, went to HD and found a slightly smaller, but similar washer to replace it and then reassembled all.
Tray opens and closes no problem now, but I do get a little DVD wobble when the disk is revving down.

I used Mike's suggestion and opened the top "flap" with a butter knife, then pushed/wiggled the loader tray with my finger while pushing eject and it worked! It works again. Guess it got jammed. Probably by my 5 year old!