Problem with blue color for Canon ip6000D

[coldlshower]

Since I bought this printer (Canon ip6000D) years ago, I had a problem with blue color.
All other colors print correct but blue sky prints more or less bluish-grey color.
I never could get blue sky.
Could someone suggest how to fix this problem?
Coldshower

 

[Tin Ho]

Do a nozzle check and check that all 6 colors of the print head fired well. Have you replaced any cartridges so far?

 

[coldlshower]

Do a nozzle check and check that all 6 colors of the print head fired well. Have you replaced any cartridges so far?

Hi, I did a nozzle check after repeated deep cleanings. The pattern after the nozzle check look fine except for C (cyan) color. C-color band looks OK but I see a few white (discontinuous) "-" lines. I could not get rid of them. How can I clean Cyan nozzle? This could be the problem but I am not sure. coldshower

 

[coldlshower]

Do a nozzle check and check that all 6 colors of the print head fired well. Have you replaced any cartridges so far?

I have Canon ip4000 printer. I compared nozzle printing patterns between ip4000 and ip7000.
I see that all colors from ip7000 is much weaker than those from ip4000.
Does this mean that print head (of ip7000) was clogged?
coldshower