Lexmark 3100 printer problem

Turn the printer off and open the access cover.
Look for any obstructions in the paper path and remove them if necessary. (It is possible to move the carrier assembly with the power off.)
Turn the printer on, load some paper, and press the Form Feed button. (On the X83, press the Select button.)
Watch the paper as it feeds through and try to determine where the jam is occurring.
Check to see if all the rollers are turning.

If all the rollers are turning, there may be something in the feed path that you can't see. Go to step 6.
If not, there is probably a feed motor or a gear problem and the printer may require service.

If the paper is jamming under the carrier assembly, you may be able to fix it using the manual feed slot.
Turn the printer off.
Take a #10 envelope and feed it through the left side of the manual feed slot until it comes right through the printer to the back of the exit rollers.
Move it up and down first, and then slowly move it over to the right side. If something is stuck under the black guide plate, this may work it loose.