Paper mismatch error

[lynne1540]

When I try to print anythng, I get the following error message:

Paper size mismatch

The paper size detected by the printer sensor does not match the paper size selected in software.  If the paper loaded in the printer is the correct size, change, change the selected size in your software.

The paper size in the printer is 8.5" by 11.00"  and the paper size I have selected is also 8.5" by 11.00"  So I suspect that something is wrong with the paper sensor.

Recently there was a paper jam in the printer and it hasn't worked right since then.  

Where can I find out where the paper sensor is to see what's wrong with it?  I am very experienced with repairing things and am not hesistant to take the printer apart is necessary.

I have tried everything reccomended. Unplugged printer for ten minutes, did factory reset, cold reset, software upgrade, All settings are correct for paper size.

[Repairatrooper]

Does the printer print any of the print job? If it starts feeding and then throws that error, likely the TOF (top of form) sensor is damaged. This will be in the paper path, usually just under the platen. These most often are an optical sensor with a flag that is activated by the movement of paper and not unusual for them to get damaged in the process of removing a jam.

[All_in_1]

In the middle of printing a 9 page report it stopped and was asking for PHOTO paper.

[All_in_1]

Where is the paper sensor located?