tape will not go into VCR?

After replacing the Tape loading belt on my Toshiba M-647 VCR, I can not load a tape into the VCR. BUT, it has loaded a few times? Reason how/why is unknown. One time it loaded and seemed to operate normally. Then the next time it loaded (after several NO GOs) it just ate the tape. Now it's back to not loading. Believe I have a physical hang-up somewhere but can't see any? Or not hitting a switch somewhere to get the loading to start. Suggestions?