If the head is still engaged in play mode, the only way to make it work is open the whole unit, and manually turn the flywheel and disengage it from play mode, by pressing stop.
Opening up the whole unit is not an easy task, but can be done with lots of care.
https://boomboxery.com/forum/index.php/topic/8850-sharp-vz-2000-strip-down-instructions/
Download the instruction the site owner fatdog put there... helps a lot!
Possibly the main belt is either slipping or broken now.
I cannot think of an easy way to get over with this issue.