Quote Originally Posted by Imprestik View Post
Under the document feeder you have a white sheet with velcro stuck to it, remove it and you will find a sensor on a slider (kind of like in the paper trays) which obviously slides forward and back

make sure this sensor on the slider is actually set in the rails themselves, otherwise you will find the sensor on a slight angle and it will come out of position by just opening and closing the document feeder causing this issue
Can you elaborate on this? I am looking at a SPDF and I do not see any sensor.