HP OfficeJet Pro 8600 print head defective ?

[glprint]

Hi there,

I have an HP Office Jet Pro 8600 N911a printer (CM749A) with firmware version CLP1CN1435AR that started to give me problems with black and white printing.

I did the manual cleaning of the heads as described in video one and video two, first injecting distilled water to expel the 4 remaining colors and then leaving the head to soak in water at 60 degrees as suggested by the HP support.

I solved the problem with the black color, but not the magenta color that already previously in the print tests was causing problems.

This is the print head at the end of the cleaning procedure and this is the test page.

Can the print head be defective?

 

[glprint]

Any suggestions on why magenta color is printed bad only on the left side, like shown on this image ?

 

[INKJET ARTIST]

This is because pre filter in magenta canal i clogged.
Just imagine what would happened in you car if you have the same problem in your fuel supply. You would be able to drive but when when you pres accelerator for power you get nothing

 

[glprint]

You mean a filter directly placed on the printhead and not on the cartridge? How do I remove it?