HP 310 Not Printing Any Cyan

Hi all, after printing perfectly on Saturday until I ran out of optimizer, my cyan does not seem to fire. I was printing a job and any blue elements were 100% magenta. I have tried swapping the print heads around with no success. Black and other colors still print perfectly. Test plots show light cyan, but no cyan. Maintenance cartridge is at 35%. New Cyan ink cartridge as of February. Can anyone suggest anything? I'm guessing a printhead, but one has 2000ml through it and the other 1100ml...I've replaced the C/K printheads multiple times since owning this printer, seems as though they do not last...

Thanks in advance.

Hello @r2prints

Having seen the images attached, I can suggest several recommendations:

3. Clean the Printheads C / K: Go to "Options> Image-quality maintenance> Clean Printheads> Clean C-K". This can prove to do it 3-4 times to see if you can recover these Printheads.
4. Replace the two Printheads. The limit of life guaranteed by HP (1000ml) has already passed. When putting the new ones, please follow the indications of the HP Latex 300 Printer User Guide, where says that you must shake vigorously before inserting them.
5. Ensure that the room's ambient temperature is within specifications. This information can be found in the User Guide.
6. If the problem persists, you should contact your Support Services, just to check if somehow there is some air inside the tubes for the Cyan line and this is causing these Printheads not to work properly. Please let me know if this information help you

It has been known that the Primer assembly can cause issues such as this if any of the rubber nibs go missing.

the primer looks like a crane above the carriage in the right side of the machine.

If you use a flash light you can look in and see if the 4 fingers all have nibs. If not then the primer needs replacing and recalibration. (the nibs are not available as a separate part)

Good Luck

RoyK