Phaser Colorstix: cyan greenish

[emxpert]

Has anyone seen this problem before?
(yes, I only use colorstix from xerox/tektronix)

Certain colors would never print right, no matter what color correction (if any) schemes were used. After printing the light stripes diagnostic sheet and comparing to one that was luckily still around from a while ago, it was obvious that cyan had taken a major shift into the green (something in the realm of "teal" or "jade" green).
My first thought was ink shelf life, but I checked all the remaining unmelted ink, and it was all still nice, bright cyan (the "crayon test".

Next, I printed a few hundred pages of pure full page cyan. The color gradually shifted back, starting with streaks of mixed color, causing me to have to go through 2 or 3 cyan colorstix in the purging process.

Any ideas on what happened and/or how to prevent it?

Thanks

 

[inktek99]

This is called "cooking" of the melted ink and occurs with both Xerox ColorStix and generic inks, especially with the cyan ink and the yellow ink. This occurs when the ink is in a melted condition for approx. 10 days or more without being used - the ink is held at a high temperature which causes the shift you observed. The solution is to print full pages of the affected color or to do 3 or more eliminate light stripes cleanings. The Phaser 860 and 8200 have a built in weekly ink purge to correct this problem. Steve