Won't play or record.

This will be a bit difficult because I can't see the unit, but here are a few ideas.
1) Did the arms that pull the tape around the head go all the way around the heads? If not, I would look at the loading motor belt. It may be slipping and not fully loading the tape.
2) Is the tape being pressed up against the pinch roller on the right hand side of the deck? If not, there is a pivot arm that is supposed to pull the tape up to the pinch roller. This arm often gets stuck in the "loaded" position and therefore does not pull the tape up to the pinch roller.

Please update this with what you see and I'll provide more details on how to address the problem.
Dan