Cyan head dropping ink

[ahmedsamy]

Suddenly the Cyan printhead in my Design jet 9000 had large gaps of white area in the test print, I run 3 strong cleaning cycles, it started printing properly then it started to drop ink on the media.
Same ink, same media settings, wipers and capping station are both clean and working properly, print head is perfectly clean, no dust or dirt on the printing surface.

Any idea what is happening?

 

[Cliff]

sound like a vac problem or a material strike, is your place dry ? static ?

 

[ahmedsamy]

Many thanks Cliff, sure it's not a material strike, vacuum is ok, material perfectly flat.

 

[printdoctor]

Hi,
On 9000 you don't have vaccum to the Ph's.
Is for sure a problem with the ink line- you get air in ink line to the PH. Check the tube connection to the PH-(is an O ring there) and also the connection to the air dumper> sub tank... pump.

 

[ahmedsamy]

Many thanks printdoctor, what I meant by vacuum, is the vacuum under the media.
I have checked all connections, O rings etc... all was fine. I have also received this comment
"Hello Ahmed,
every printhead has a "non-wet-coating" to keep the ink aerosol away from the nozzle outlets of the head. If this coating is destructed, during printing the ink is building up at the nozzle surface and also directly infront of the nozzle outlets. From that moment on the nozzle isn't firing the ink on the print media but in the drop. With every ink shot the drop becomes larger and larger until it is falling down on the substrate. In most cases the drop is falling when the head carriage changes its direction for moving back.
So the solution for you will be to change the head.
Best regards
Christoph"

 

[Cliff]

Also meant vac for material,.....

easy to check head, flush and change with another color ( ofcourse power down first ) if problem moves then its head related if not it could be supply

 

[ahmedsamy]

Thanks Cliff, worth the try

 

[Alan812]

If your head has dampers (filters), they could be clogged.

 

[Corey]

What kind of media are you printing on?

 

[ahmedsamy]

Dear all,

I finally reached the cause of the problem, it's a tiny crack in the Cyan tube where it meets the plastic rail in the middle of the printer.