epson 9700 whole yellow channel

[artbhai]

hello
after giving 8 months of good service on sublimation ink, our 9700 has developed a problem.
about 2 weeks back, while printing solid yellow patch, one of the yellow channels went blanc. (printer has 5 colors and 10 channel--- 2 channels per color).
found it during nozzle check as color changed in the print.
pair cleaning and normal cleaning did not make any diff. power cleaning made the channel come back. but after a few prints, again bottom half of the same channel went blanc.
if there is less yellow ink in the file, it works ok but as soon as a solid yellow patch and same problem. only that channel. sometimes only bottom 4-5 lines of that channel.

we changed dampers. it worked well for 4-5 days. could print solid yellows in prints but after a week, same problem. (the dampers were not original but chinese)
AS there is problem with only one channel of yellow, i suspect it has to do something with air leakage after the yellow line bifurcates. or the damper.
we dont have epson support (as we use sub ink)but a good mechanic helps us with change of dampers or any spare part.
any idea changing which part will solve this?
1. dampers
2. oring (dont know where that is)
3. capping
4. head cable.
kindly suggest..

rahul
ps - we are prinitng 720x720 bi mode , we have wasatch rip.

[wandrercat]

Hi Rahul,

Facing the same dilemma with Epson 9700 as yours.I am a tech for similar machines but this machine is totally packed viz ink system.There is probably no way to find why the yellow or other ink channels drop out during printing.
Did you find the solution?

Regards

Usman