Ink Cartridge Refill Help Center

Printhead Diagnostics & Failures

Individual ink cartridge series printer models, for example all inkjet printers that contain 4, 5 or 6 ink cartridges, have an electronic PRINTHEAD (separate ink and silicon electronic assembly) located within the base of the carriage assembly. The PRINTHEAD is responsible for pulling ink from all the ink cartridges and then firing the ink droplets onto the paper – this semi-permanent or permanent electronic assembly will eventually fail, over time, depending on print usage type and printer duty cycle [i.e. while some are rated for up to 40,000 printed pages (i.e. HP OJ PRO L Series models), others are rated a few as 3,000-4,000 printed pages (i.e. HP Deskjet 3520 model)].*   The PRINTHEAD may or may not be customer replaceable – check your User Manual. If replaceable, a new PRINTHEAD may be orderable from the printer manufacturer (or third party sources such as or  Some of the more common replaceable consumer inkjet PRINTHEADs are pictured below….





HP 940 PRINTHEAD (Yellow/Black or Cyan/Magenta)


EPSON PRINTHEAD (NOT easily customer replaceable!)


For an ‘Unrecognized Cartridge’, ‘Missing or Damaged Cartridge’ or similar cartridge failure detection alert message (i.e. Red X displayed, etc.), if the problem cannot be resolved by replacing the ink cartridge with a different cartridge or manufacturer’s new original/genuine ink cartridge, then typically there is a connectivity problem between ink cartridge and the built-in PRINTHEAD (i.e. cartridge smart chip contacts, printhead electrical contacts or carriage electrical contacts are dirty with ink residue and/or dust) or the PRINTHEAD has internally failed*. If cartridge replacement does not remedy the issue, then it is suggested to remove all the ink cartridges and PRINTHEAD.  Thoroughly clean the electrical contacts on the PRINTHEAD assembly (i.e. gold contacts) along with the gold electrical contacts on the carriage assembly.





Missing Colors & Poor Image Quality:

To help overcome severe print quality performance, it is suggested you activate the printer’s internal printhead/nozzle clean procedure. It may also be necessary to perform a hot-water flush of the built-in PRINTHEAD (semi-permanent or permanent). Refer to links below for your manufacturer/printer type.

Partially Jetting Nozzles


Printhead Cleaning & Flushing:

HP 564 Ink-Series Printer Models


HP 920 Ink-Series Printer Models


Canon Printhead Flush Procedure


Epson Printhead Cleaning



HP Printhead / Printer Diagnostic Tests:

To troubleshoot PRINTHEADs found in HP printer models, please refer to HP Printer Diagnostics (otherwise refer to ‘Solve My Problem’ for all other printer models):

HP Printer Diagnostics



Refilled Cartridge Troubleshooting Table:



For refilled HP 934/935, HP 950/951 or HP 970/971 ink cartridge series printer models which display printer/cartridge error messages such as “cartridge missing or damaged”, “cartridge problem”, “cartridge depleted”, etc., and printing is not permitted, there is a new printer firmware update available for your printer model which will enable refilled ink cartridges to function normally (released Sept. 19, 2017).  Click on the link below; this will explain the issue & offer a printer firmware download to fix the issue and allow you to continue using refilled ink cartridges: click here



HP 950-951 ink-series printer models:

HP OfficeJet Pro 8100 Printer ( N811a ), HP OfficeJet Pro 8600 Printer ( N911a ),  HP OfficeJet Pro 8600 Plus Printer ( N911g ),  HP OfficeJet Pro 8600 Premium Printer ( N911n ),  HP OfficeJet Pro 8100 Printer ( N811d ),  HP OfficeJet Pro 8610 eAIO Printer ( A7F64A ),  HP OfficeJet Pro 8620 eAIO Printer ( A7F65A ),  HP OfficeJet Pro 8630 eAIO Printer ( A7F66A ), HP OfficeJet Pro 251dw Printer ( CV136A ), HP OfficeJet Pro 276dw  MFP Printer ( CR770A ), HP OfficeJet Pro 8610 eAIO Printer ( E1D34A ), HP OfficeJet Pro 8615 eAIO Printer ( D7Z36A ),  HP OfficeJet Pro 8616 eAIO Printer ( J5T77A ), HP OfficeJet Pro 8625 eAIO Printer ( D7Z37A ), HP OfficeJet Pro 8640 eAIO Printer ( E2D42A ), HP OfficeJet Pro 8660 eAIO Printer ( E1D36A ).


HP 932-933 ink-series printer models:

HP OfficeJet 6100 eAIO Printer ( N611a ),  HP OfficeJet 6600 eAIO Printer ( H711a ),  HP OfficeJet 6600 e-All-in-One Printer ( H711g ),  HP OfficeJet 6700 Premium eAIO ( H711n ), HP  OfficeJet 7110 Wide Format ePrinter ( H812a ), HP OfficeJet 7610 Wide Format e-All-in-One ( CR769A ).


Canon 250-251 ink-series printer models:

Canon Pixma MX922 Printer, Canon Pixma MG5420 Printer, Canon Pixma MX722 Printer, Canon Pixma MG5450 PrinterCanon Pixma MX725 PrinterCanon Pixma MX925 PrinterCanon Pixma iP7220 PrinterCanon Pixma iP7250 PrinterCanon Pixma iP8720 PrinterCanon Pixma iP8750 PrinterCanon Pixma MG5520 PrinterCanon Pixma MG5550 PrinterCanon Pixma MG5620 PrinterCanon Pixma MG6320 PrinterCanon Pixma MG6350 PrinterCanon Pixma MG6420 PrinterCanon Pixma MG6620 PrinterCanon Pixma MG7120 PrinterCanon Pixma MG7150 PrinterCanon Pixma MG7520 PrinterCanon Pixma iX6820 PrinterCanon Pixma iX6850 PrinterCanon Pixma MX922 PrinterCanon Pixma MG6450 Printer  


Canon 550-551 ink-series printer models:

Canon Pixma iP7250 PrinterCanon Pixma iP8750 PrinterCanon Pixma iX6850 PrinterCanon Pixma MG5450 PrinterCanon Pixma MG5550 PrinterCanon Pixma MG5650 PrinterCanon Pixma MG6350 PrinterCanon Pixma MG6450 PrinterCanon Pixma MG6650 PrinterCanon Pixma MG7150 PrinterCanon Pixma MG7550 PrinterCanon Pixma MX725 PrinterCanon Pixma MX925 Printer 






*Typically the average manufacturer’s PRINTHEAD should not reach it’s end-of-life until after a minimum of 8 or more complete sets of cartridge changes. The printhead will eventually fail in time due to an internal micro-electronics failure, due to the following leading factors: general customer print usage and printer care, printer duty cycle (i.e. # pages printed per month), printing frequency (i.e. time between each print job), print mode (i.e. draft vs. normal), type of content printed (i.e. photos vs plain pages) and print color mode (black and white only vs. color/greyscale printing). Paper types used (i.e. plain paper, photo papers & matte/heavy bond papers) and paper edge curl (i.e. duration in printer and/or exposure to low relative humidity) can also quickly lead to premature printhead failures due to physical ‘head strikes’ of the paper edges making repeated contact with the printhead nozzle plate surfaces. Only use manufacturer recommended paper types and thicknesses (i.e. most A4 inkjet printers support up to 20 lb plain bond paper) with your printer.

CAUTION: When refilling your ink cartridges it is advised to only refill with reputable sources. Based on 3rd party testing, incompatible ink formulations (i.e. those which contain VOC’s or volatile organic compounds which contain trace amounts of solvent chemicals) have been found to cause permanent damage to the built-in inkjet PRINTHEAD.

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