I get a vertical black line when I try to scan a document.

The first step is to clean the glass in the scanner tray with a mild cleaner. If that does not correct the line, then you could try a Duster spay can (CRC Duster or Ativa Cleaning Duster, etc.) to try to blow on the arm that moves under the glass. Be careful as the can should be used in short spurts or it will get very cold and stop spaying or freeze something in the machine.

If still no luck, try to see if this site will properly guide you:

http://h10025.www1.hp.com/ewfrf/wc/product?cc=us&dlc=en&product=390315&lc=en&jumpid=reg_R1002_USEN

Good luck..................Pete