|It worked OK previously? I mean, is this camcorder new to you and maybe you're just not doing it right or have you had it for quite awhile?|
I don't understand why you can get a cassette out but can't put one in. The door has to be open to get it out so what's stopping you from putting another one in? And how are you getting it out or opening the tray to get it out? Maybe it's just my unfamiliarity with it but jeez, explain things a little better.
That said, I know with the old VCR's there were LED sensors that told it when a tape was in. If one of those went bad you ended up with it not opening and a tape being stuck inside. Maybe that's what's happening with yours.
Or since it's a mechanical process maybe something got bent or the motor went bad.
Or maybe the button on the back is bad.
Certainly without more information there's no way to know exactly what the problem is.