I have a Brother HL-4040CN.

Question

I have a Brother HL-4040CN. It says there is a rear paper jam. I opened the back, cleared the paper and reclosed. The error message won't clear. I have taken all the removable pieces, front and back out to search for bits of paper to no avail. There is no paper anywhere, I checked between the rollers very well. I suspect the sensor is stuck. Any Ideas?