3420 cartridge incompatible??

[Kent]

After starting my computer and doing one print job, my HP 3420 printer
control software is giving me the message "Incompatible black print
cartridge" and it will not print. If the system is restarted, it will
again do one print job before failing in the same way. This cartridge
came with the printer when new and has been refilled twice. I have
not had any other problems with it. I hesitate to buy a new cartridge
because it may still give me the same message. I would really
appreciate any help with this. Thanks.

 

[Kent]

The solution I discovered is to rub the contacts on the cartridge with
a pencil eraser and rub the contacts in the cartridge holder with a
Q-tip. This cleaned the contacts and it works fine now.