Yellow print head problem: letting cyan through ROLAND VERSA ART RS640

[messmedia]

Hello.
I'vo got little problem today.
My Roland nozzle check print shows that bottom two lines in yellow part of pattern are greenish, as if they are mixed with cyan.

What can be a problem?

 

[Dave L.]

Post a test print so we can see please.

 

[J Hill Designs]

possible cross contamination due to swollen capping sponges