HP Support – 564, 902, 910, 920, 934, 935,

Following a firmware upgrade on selected printers utilizing the following cartridges, 934 / 935 / 950 / 951 / 970 / 971 some cartridges suddenly stopped working.

HP indicated in a statement that the reason for the upgrade was to protect the security chip. However, this upgrade was done automatically and without customer consent. Consequently, millions of customers across the world were all the sudden unable to print. So, under pressure from all the different consumer groups, HP announced that they would release a firmware to reverse the unsolicited upgrade. Those upgrades are now available on the HP Support website under the client’s specific printer model.

A procedure is available with a link to the different printer models. Simply follow the instructions for the upgrade/downgrade.

 Visit this link to know the procedure for your printer model :


Printhead Cleaning

Solution: Try running 1-2 print head cleanings. Below are general instructions for how to perform a print head cleaning, however this is done in different ways on every printer, so consult your manual for exact steps.

On your printer:

To perform a Printhead cleaning on your printer go to: Settings-> Tools-> Cleaning / Clean Printhead.

You may need to perform this more then once if you have not used your printer in a while or have left the printer without cartridges installed for some time.

From your computer:

1. On the computer, click Start, then click on Settings/ Control Panel.

2. Select Printers and Faxes (On Windows Vista, select Printer under Hardware and Sound)

3. Right-click on your printer, and click on Properties. 4. Select the Maintenance / Service tab, then select Print Head Cleaning.


If you receive this error message after installing a new compatible ink cartridge this is completely normal. Just press the OK button on the printer to acknowledge this message. You will now be able to print.

If you receive this error message please first check that you have the correct cartridge in the correct location in the printer. The printer will tell you which cartridge is giving the error and it would be very unlikely for all the cartridge to give this message. If you have the correct cartridge in the correct location then most likely the chip on the cartridge has failed and you will need to buy a new replacement cartridge. Please return the cartridge to Printer Refillers with your original receipt for support.

Is your error not listed above? Contact our tech support!

Please contact our tech support (right->). Please give us as much detail as you can and we will look into your issue and get back to you as soon as possible.

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