Are you saying that when you started this thread on 9/26 after you had missing nozzles and already installed PiezoFlush, that on 10/12 you had a nearly perfect nozzle check with only one individual C nozzle missing, but it got worse again- or the C is improved, but you are now having troubles with another position (you mentioned K above)? Did you clean the capping station, wiper blade, flushing box and bottom of the print head? If so- what were your results after cleaning? About how old is your printer, and has it ever had any new parts installed?
I reviewed your order history and see you started buying ConeColor inks from us in July 2012, and have bought a set of 1000ml, 110ml, 700ml + most recently 350ml set of ink bottles since last Summer. I only see one cartridge listed on your order history, so am curious what cartridges you’re using.
After several years of constant use, our 7900 is just showing signs of needing the dampers replaced, so I am preparing to do this repair myself (and will take photos to document the process). The ink selector unit costs about $175, and contains all the dampers to connect the ink lines to the print head. I quickly read thru the process in the repair manual, and will be ordering the part very soon. What I will do, and suggest others do- is to replace the selector unit, and flush the print head once it’s accessible and the dampers are disconnected, then connect the new dampers/selector unit. The wiper blade should be replaced at the same time, and I am looking into the cost/process incolved in replacing the flushing box, wiper blade, capping station assembly.
Please let me know, so I can try to help you past this.
Best regards~ Dana