Technical information

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both PRINTHEADS will eventually fail depending on printed content, printer duty cycle (i.e. typically
rated for ~41, 500 printed pages depending on image content & frequency of printing). The average
inkjet printer can typically be refilled with ~20+ 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
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 3rd party PRINTHEAD priming tool, such as this one:
http://www.inkowl.com/?p=product&product=5035
A PRINTHEAD "missing" / "damaged" / "problem" error has nothing to do with the HP88 refilled ink
cartridges since these are just plastic tanks which hold ink - all ink formulations have been fully tested
for compatibility with all HP printer systems. The timing of a printer/printhead failure is merely
coincidental with respect to the use of refilled ink cartridges. Each PRINTHEAD is a complex electronic
ink-firing assembly which sits directly behind the ink cartridges during the printer idle state; the
cartridges plug into and feed ink to both the Yellow/Black PRINTHEAD and Cyan/Magenta PRINTHEAD.
7. If the above resolutions do not correct the issue, then replacement of the suspect PRINTHEAD may
likely be required. As the refilled ink cartridge has nothing to do with the failure of the electronic
PRINTHEAD assembly, printhead replacement cost is not covered. All printheads will eventually fail
depending on printed content, usage and time via natural electronics degradation. The Inkjet411 test
labs have never observed a correlation between a refilled HP88 cartridge and the failure of the HP88
PRINTHEAD assembly. We trust you clearly understand our position with respect to this type of micro -
electronics failure of a PRINTHEAD, should this turn out to be the root cause of failure.
8. If problem persists after following all suggestions above, then we suggest you discuss the possibility of
a refund with your local Costco (for the refilled cartridge purchase). We apologize for the inconvenience
this may have caused you.
Please let us know if you have any further questions on the technical information provided. For any
additional questions please contact us directly: [e-mail]
-Thank you
HP OFFICEJET PRO 8500 (HP 940s) – POOR PRINT QUALITY / IMPROPER OR MISSING COLORS
Regarding your recent inquiry about the HP940 poor print quality problems ("pink color output"), it
sounds like the Cyan/Magenta OR Yellow/Black PRINTHEAD is causing the problem or there are air
bubbles in the ink lines/PRINTHEAD assembly. This problem is normally caused by an ink deprime within
the ink system and is normally recoverable. Refer to the following suggested actions:
1. Activate a 'Clean Printhead' routine, 2 to 3 times in a row, from your TOOLS/MAINTENANCE menu, to
see if this corrects the problem. This action will perform a printhead prime and try to re -establish proper
internal pressures – this action will consume approximately 10% of total ink from each ink cartridge.