OfficeJet 8620, new HP 950XL, "one or more cartridges appear to be damaged." All NEW HP cartridges.

[laxtech]

Officejet 8620 printer. This printer was working perfectly for years, then suddenly stopped working and showing the above error message about one or two months ago. Today I replaced the black cartridge with yet another new HP 950XL cartridge, but printer STILL reports "(K) One or more cartridges appear to be damaged. Remove them and replace with new cartridges." The only problem cartridge shown is the black cartridge, shown by a (K) on the screen, above the error message's text.

I have tried:

 1) Removing power cord while printer is on, left print disconnected for >5 mins. PROBLEM STILL EXISTS.

 2) Tried updating firmware via FW update downloaded from HP. FW update app will not update printer; reports "Not applicable" and shows printer's current fw to be FDP1CN2022AR.

 3) Tried updating firmware via printer's online update. Reports that FW is current and no update needed.

 4) Tried an old 950XL cartridge. Printer accepted cartridge and showed no error UNTIL I tried to print, then got same "...cartridges appear to be damaged" message.

[laxtech]

Following up, looking at the Ink Cartridge Status page via printer's webpage, I see that the NEW OUT OF THE BOX 950XL cartridge is showing no info and (apparently) not recognized as an HP item. See pic.