Technical information

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ii. If you observe an ink cartridge “EXPIRED” error (error lights/blinking pattern), hold the power
button and push resume 3 times. Release power button and the printer should reset.
If none of the suggestions above remedy the issue, then it is possible that the smart chip(s) on the
refilled ink cartridge(s) got somehow electrically damaged, thus rendering them useless (i.e. what we
generally refer to as physical damage). It is suggested to replace suspect ink cartridges with brand new
HP Genuine 940/940XL ink cartridges (i.e. original) and retest.
NOTE 1: Each cartridge also has an internal ink monitoring sensor at base of cartridge that detects
whether ink is present at the cartridge, this in turn feeds ink via the ink port and into either of the 2
PRINTHEADs. If a cartridge truly is out of ink or near empty, you will receive an “INK DEPLETED”
message, or similar. When this occurs the printer will refuse to print in any color or print mode. You may
also observe the following message: "The Device Needs attention". The ink lines/channels between the
4 cartridges and the 2 PRINTHEADS must always be properly primed with ink or air gaps could form and
deprime either one of the PRINTHEADs. When a PRINTHEAD has difficulty maintaining adequate internal
pressure, ink depletion errors can be encountered and the PRINTHEAD may need to be replaced
(available from HP.com). Refer to NOTE 2.
NOTE 2: All HP 940 ink-series 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 ~20,000 printed pages depending on image content & frequency of printing, though
HP has reported PRINTHEAD failures with as few as 3000 pages). 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). If the ‘CLEAN PRINTHEAD’ function (under Maintenance Menu) does not correct
the issue then a new PRINTHEAD may be required. It may be possible to recover the ink system using a
3
rd
party PRINTHEAD priming tool, such as this one (…thought this tool has NOT been endorsed or tested
by the Inkjet411 labs): http://www.inkowl.com/?p=product&product=5035
Please let us know if you still cannot resolve the current issue or require further assistance. For any
additional questions please contact us directly: [e-mail]
-Thank you
HP OFFICEJET PRO 8500A (HP 940s) – “NO INK” / “MISSING OR DAMAGED” / “Expired” PRINTER ERROR