cartridge alignment failure

This is a HP Officejet 6110 all in one unit.  It is about 18 months old but with light usage.  The black cartridge needed to be replaced.  It was replaced with a new HP 56 cartridge but upon depressing the enter key to cause the printer to do a "print cartridge alignment", the unit returns an error message...."print cartridge alignment failed"..."Press enter to align print cartridges".  After several attempts to do so, I again checked the cartridge to be sure that we had installed the correct one, made certain that the protective tape was removed, cleaned the electrical contact areas on both of the cartridges and their bays and then tried to do another print alignment.  It again fails.  I unplugged the power from the unit as well as the printer cable for about one minute, and then repowered the unit.  This also did not help.  I inserted another new HP black cartridge...that too did not solve this problem.  I ran a cartridge clean routine, but that didn't help either.  

Interestingly,  the unit appears to print OK but the message within the unit continues to say that we need to press the enter key to align the cartridges.  Any suggestions on how to make this message go away?  I assume that the message is correct regarding the alignment failure which would indicate that something is not right with the unit.