My HP Deskjet F4240 keeps displaying an error message with an "E" in the screen next to the Copy buttons and with the power button flashing. I've tried running several troubleshooters, updating the driver, and nothing works. At first the issue seemed to be the ink, but I have replaced the ink cartridge and now the HP Support App says that "The cover is open." However, no cover is open and I've tried opening and closing it many times as well as cleaning the area in case the was preventing the sensor from having an accurate reading. Any help would be much appreciated!