4880 based printer ink lines problem.

Hi guys,

I was reported this problem here in the past and I have been fighting with it for months. At first it was just a black ink line but now it is almost all lines on the left hand side of the printer except one CYAN line.

So here is a problem. When my printer sits without printing for 2 and more days three lines out of four on the left side stop supplying any ink. It either seems there is no ink left in dampers at all or at least there is a very big gap with air inside these three lines between corresponding cartridges and the dampers.

After I do not print for 2 and more days I have to run power cleaning to get all dampers charged with inks. Then I can print with no gaps in nozzles. If I do not do power cleaning these three lines show very little or no ink at all in nozzle check(see attached image).

My guess that during power cleaning all lines and dampers are charged with inks without any problems and I can print with all colours(see attached image with nozzle check) but then after some time somehow I have no ink left even in some dampers.

I have replaced dampers and connectors twice, capping station once and even replaced all tubing as the last attempt to fix it but I have not fixed the problem. In fact I may be even have made it worse because before I had this problem only with black ink but now extra two lines(Magenta and Yellow) are showing the same problem.
Surprisingly there is no such problem with CYAN that sits on the same side between Magenta and Black. The right side with two white and LC and LM seems to be perfect all the time.

I must add that MFG for this printer has changed the way inks are supplied to the print head. Instead of getting the ink from the back of ink cartridges ink tubes go into the holes located at the top of each cartridge(see attached image). I do not think that it can cause all these problems.. except all ink tubes at some point located higher than the print head.. but this design causes a lot of ink wasted during power cleaning. Mostly because when you asked to get these blue levers up which I believe should close the lines they stay open and inks are sucked into print head all the time. I have measured how much ink I waste during power cleaning and it seems to be 200ml.

Has anybody ever experienced something like this? If yes what is the problem here. I want to fix it but I have no idea what can cause this problem.
Also with my current ink supply design, is it worth to change it back the way it is originally done in 4880? It is a bit messy the way it is now plus power cleaning cost me at least $40 based on the ink cost of $200/L

BTW, the ink I use is UV ink. Never seen them clogging ink the print head. The right hand side colour do a perfect nozzle check print even I do not use the printer for a month. At least I can say it about LC and LM because other two channels are white and is it hard to see.