[SlideCube] stuck cube projector

[Dogtalk]

Borrowed one that's been on the back shelf many years. Squueze the Advance
button and a nasty sound like an electric buzz.  The only part that I can
see moving is a tiny metal "tab"  inside the projector and near the front of
the machine and close to the preview platform.  Can't get the slide to move
nor can I push it in manually. Not sure where it should be for projection
anyhow.  Solutions?

Thank you so much for maintaining this list.

E. Rosenberg, Oakland, Ca.