HP 4200 Problem

[TAXAD01]

The wheels in the output tray of my HP 4200 printer quit spinning causing the paper to stop midway through the printing process. What would cause this? If I open up the back feed door to bypass the front output tray, it works fine. Thanks.

[redcow]

Those "wheels" are on a shaft. The right end(as you face the printer)of this shaft has a gear that is driven by a bigger gear. That gear at the end of the shaft may have popped out of the assembly
that it sits in, causing no contact with its drive gear.
If you have never taken this assembly out before don't do it now. You can lose parts and cause a bigger problem.
Have someone look at it. It should be a simple fix.

[TAXAD01]

The shaft gear on top appears to be engaged - I also noticed the wheel/shaft assembly on the back of the fuser does not spin when I power up (like it does on my working 4200.