First you should check the document sensor actuation lever for possible misaligned, blower the sensor itself for possible dust, check wiring connection, update firmware, or worst try to isolated the board where the sensor is connected.
We are not really familiar with the HP inkjet printer but mostly in a scanner failure problem. you need to check on the flat flex cable of the scanner bulb. you may cut the end of the flex cable so that the contacts will be fix
The scanner bulb failed to find it's home position, double check on the mechanical parts of the scanner assy it might be stocked up, check also the flat flex cable of the scanner bulb, or cleaned the white strip home position for the scanner under the platen glass.... or try to isolate the issue. it is related to the scanner assembly
