Won't turn off after shredding in automatic mode

Blow out the sensors with some compressed air, Using a can of compressed air, look for the sensors that detect the paper and give them a blast or two, then try it, it may take a couple of tries.
This may also be a good time to lubricate the cutting heads, if it is a good machine with metal heads a light oil applied to paper then run through the shredder will pass the oil onto the heads.
A shredder oil or light oil like 3 in 1, these usually have a narrow nozzle to limit the oil flow, draw lines, do a picture or spell your name on the paper with oil and shred it. You have just serviced your shredder.
If it is a less expensive shredder with plastic heads, shredding a couple if sheets of waxed paper will pass the wax onto the cutting heads reducing friction.

Hope this helps.
Ed

I was able to pull really hard and open the bin 1-2". I turned the unit on its side over the trash can and some shreds came out. I alternated shoving a sturdy metal rod inside (first an aluminum architectural ruler then the longer handle of a squeeze clamp) to loosen up the shreds and tipping the machine on its side to get some loose shreds out. After doing this enough times I was able to dislodge the dense clumps and remove the drawer. Now that the machine is empty there is a red light on and it does not shred.....UPDATE: turns out somewhere along this rough process (paper was in rock solid clumps) a small piece of the door that presses the "door closed" switch broke off. Jammed a piece of cardboard in there and it shreds again, although it does not automatically turn off when the door is open.

try cleaning auto feed sensors

Blow canned air down into the feed slot.

Thanks for taking the time to leave a good tip.

this is an issue with your paperfeed sensor. You need to call Fellowes at 1-800-945-4545.

I personally work with Fellowes brand shredders, but it sounds like you have a paper feed sensor issue. This may be a mechanical or electronic sensor located in the center of the paper feed slot. If it is electronic it may just need cleaning(qtip dipped in rubbing alchohol. If it is a mechanical sensor check to make sure it has not been broken or it may be stuck because of paper that has become wedged behind it(you may need to jiggle the switch a few times to free it). If none of this works you may have a burned out switch or a bad pc board, contact manufacturer for more info.