Missing Orange Segments on my P400

[Charles218]

I use the InkJet Plumber App to do print test pages every 50 hours or so, it's a great little app. I recently found that it had stopped working and for a couple of weeks or so no test prints were fired. Several of the colors were clogged and all brought back except for orange. Using both Piezo Flush and also pushing air through the cart with a syringe has not helped to get orange back, about half the segments are missing. When pushing air I get little to no resistance and the paper towel under the cart is saturated with orange, I follow this with a head cleaning then test print. How do I get the orange back?

 

[Ink stained Fingers]

Pushing air tlhrough the nozzles - ? I rather would connect a syringe directly to the ink receptactle in the carriage , and not through a cartridge - and alternatively pushing gently and sucking a cleaning fluid several times, and with the last stroke a push to have a liquid - and not bubbles - in the ink channel. I got my P400 longer time ago working all the time although I was changing, mixing and testing various inks a lot.