Hello,
We have a Sony DVP-NS728H that is for the kids to use.
Somehow the tray lock/child lock has been turned on.
We have gone through the manual & done as instructed (return, enter then power) with various versions of but to no avail.
This has been a great little dvd player & it seems a waste to condemned it to the bin for a little niggle.
If any one has any advice on the matter then please let us know.