One sunny morning – i suddenly got an 0x007C9C98 Error on my (old) HP ENVY 4500 printer. I didn’t throw the printer away, so i tried to repair it. (yes it’s possible)
I did the following:
First: Open the Printer (it’s easy) How? Have a look at this video: https://www.youtube.com/watch?v=gZUo2uB4uiQ
Secondly: Start the printer without the scanner attached. (just unplug the black ribbon cable on the right)
Third: The printer should start normally. (without a Error Code) Now you know: it’s the scanner.
Fourth: Open the scanner unit. (again: have a look at the video) The scanner circuit board will come free. Have a look on it: is everything on the right spot, everything pluged?
Fifth: Reassemble the scanner unit. The scanner circuit board (scanner-sleds) should be put back in the middle of the body-case. Plug in the scanner unit. Plug in the printer. Start the printer.
Done. Your printer should start normally.
Furthermore I would suggest a firmware update: support.hp.com
