error message "Install black cartridge"

[pat3743]

I installed 2 new black HP 85A ink cartridges so far and keep getting the error message "install Black Cartridge".  There is no paper jam and no packaging material is on the new cartridges.  I re-booted the printer 3 times by unplugging and re-plugging directly into the wall.  The error continues and therefore, I cannot print. 

[east2100]

Take right & left cover off first then look from rear side and take the metal cover off - with total three screws.

Look into the right most bottom side there're two black sensor there, make sure there's nothing broken or stuck or something else dropped into there.

What's in the picture is HP LaserJet P1006 which looks alike M1212. Both of them have same functional parts.

[east2100]

If the problem persisting check here to see if it helps.

https://h30434.www3.hp.com/t5/LaserJet-Printing/Printer-cnts-to-state-quot-install-new-cartridge-quo...