You can look for a small piece of paper that might've come off during the jam. If it's a sensor or switch, then it's a matter of finding out which one it is. The sensors are usuall located near the paper roller (all around it, check top and bottom) and near the paper exit, with perhaps one or 2 inbetween. Without having the actual printer right in front of me, it's hard to know exactly where to look. Be extremely carefull when looking for these switches, as there's all sorts of small moving parts and springs that are fragile and can be next to impossible to replace. Also be careful if you have to remove the housing of the printer to access it to search for the sensors/switch.
If a sensor or switch is broken, you can order a new replacement for it, just beware that the cost of the part and the time and effort that it'll take you to replace it, it might just be easier to get a new printer (unless it was an expensive printer).
Let us know how you fare with this! Good luck, hopefully it's something really simple!
War produces veterans, wounded both physically and mentally. They have sacrificed for us.....and it is now our job to help these veterans, as they have already helped us in ways we will never know, in ways that we cannot fathom, and in ways that we take granted every day.