CAUSE:There are two types of D-max adjustments in the Service Mode, which are "copy" and "print". When they are not same value, color variation could occur.Symptom is related to the Image Stabilization.
Example:
1. Image Stabilization when main SW ON refers to D-max "copy".
2.After 100 pages of multiple "Print Job", and Image Stabilization is activated after page 75 is printed out (SPAN 1 is chosen), Image Stabilization refers to D-max "print" because the "Print Job" is ongoing.
3.From page 1 to page 75, printed asD-max "copy", but from page 76 and onwards, Image Stabilization refers to D-max "print".Therefore, color variation could occur between page 75 and page 76.

Notes :
a. As a condition of the above, Image Stabilization "Long" is activated between page 75 and page 76.
b. If Image Stabilization "Normal" is activated,color variation does not occur.
c. A condition of activating "Long"would be if a certain level of print quality change (image density) could be detected during multiple print/copy job.

SOLUTION: As a workaround, the same value should be set between D-max "copy" and "print".