Technical information

240
240
NOTE 1: HP does not allow an automatic reset of the HP 940 electronic chip on the cartridge after a
refill, so the ink level indicator is sending a false message that the ink level is low. Your cartridge is not
low on ink, and nothing is wrong with your printer or cartridges. The ink level indicator usually cannot be
manually re-set, so the ink level indicator is often not usable. However, losing this feature is not
necessarily significant, because the ink level indicator usually has substantial usable ink remaining when
it shows "low on ink". If you observe "Unauthorized ink", "non-HP ink", "counterfeit ink" or similar
messages, you may ignore/dismiss this message by pressing 'OK' once for each cartridge, so that the
printer resumes its normal operation.
NOTE 2: The HP 940 printer models have two electronic PRINTHEADS (each of these electronic devices
are responsible for pulling ink from the ink cartridges and then firing the ink droplets onto the paper) –
both PRINTHEADS will eventually fail depending on printed content, printer duty cycle (i.e. typically
rated for ~30,000 printed pages depending on image content & frequency of printing). The average
inkjet printer can typically be refilled with ~8+ complete sets of ink cartridges over the life of the
printhead, after which, either the Yellow/Black and/or Cyan/Magenta printhead may need to be
replaced (available at HP.com). Refer to video on how the HP PRINTHEAD functions:
http://inkjet411.com/?page_id=2054
NOTE 3: When the PRINTHEAD electronically fails typically the printer will provide an alert message
when this happens, but if a printhead has suffered a deprime (i.e. loss of ink/pressure which results in
no printing of color), it is possible to recover the system using a 3
rd
party PRINTHEAD priming tool, such
as this one: http://www.inkowl.com/?p=product&product=5035
Please let us know if the problem persists. For any additional questions please contact us directly:
[e-mail]
-Thank you
HP OFFICEJET PRO 8500/8500A (HP 940s) – CONFUSION OVER INK LOW AND CHIP REPLACEMENT
Regarding your recent inquiry about the HP 940 cartridge low ink message, HP does not allow an
automatic reset of the electronic chip on the cartridge after a refill, so the ink level indicator is sending a
false message that the ink level is low. Your cartridge is not low on ink, and nothing is wrong with your
printer or cartridges.
Your printer/computer will display “ink alert” message(s). Press ‘OK’ to dismiss this prompt. Additional
alert messages, such as “non-genuine cartridge” or “fraud” may also be displayed. Press ‘OK’ or ‘Dismiss’
to bypass these prompts.
However, if you observe strange printer behavior or encounter ‘unrecognized cartridge’ or ‘expired ink’
alert messages, perform the following steps: