I have a three month old HP ENVY Inspire 7900 printer. I need to use the document feeder to scan documents. It has worked in the past month. The printer acknowledges that the document is in the document feeder correctly. When I select the scan button the printer immediately starts scanning the flat bed and doesn't even try the document feeder. Knowing that, I still did everything Google said to do. The paper is correct, clean and properly entered. The rollers have been cleaned. The printer has been unplugged and reconnected. The computer is accepting and correctly filing the blank scans the printer is sending it. What else do I need to do?