79 Service Error

[LoisDowney]

Wi-fi network was set up virtually by an HP technician when new HP computer and printer were purchased -- just under a year ago. (He tried to set up direct wi-fi, but could not get it to work, so he set up the network.) Everything worked perfectly until about a month ago, when the printer stopped printing, the computer indicated that the printer was off-line, and the printer control panel indicated a 79 Service Error. The printer is linked to an HP ENVY All-in-One-27-b245s with a Windows 10 OS.

I have followed all the suggestions I can find online:

Ran a printer power cycle (several times, and rebooted my computer many times).

Made sure the printer was set as the default.

Made sure the computer and printer were both on the same wi-fi network.

Reset the Print Spooler service.

Removed and re-added the printer.

Took the printer to a repair shop, where they "flashed firmware".

Attempted to follow the instructions at https://support.hp.com/us-en/document/c05029970 . However, that document indicated that I should check the firmware version that is installed. The only instructions I found online for checking the firmware version was to print a configuration page; when I attempt to do that, I just get the 79 Service Error on the printer control panel and no configuration information. The document also provided a link that was supposed to indicate the latest firmware available. However, when I click that link, I get an indication that the page does not exist.

Does anyone have any additional ideas (short of just running a cable from the computer to the printer) for how to fix this problem?

THANKS!!