[CQ] c300 losing yellow image during copying.

[copiers4africa]

hi everyone i have midboggling problem which i have managed to resolve to some extent.
c300 which irraticly losses its yellow image density completely or a times gradually.

i replaced new yellow image units and replaced toner suplly unit with motors to solve this problem.each time i do the gardations the machine allows the values to change.but when i do the high compression gradations then the machine losess the yello image.

i nvram cleared the machine and toned up the units actdc and toner ratios are appr.9percent...

replaced printer contol board and updated firmware..
tcr sensors are fine and idcs are fine...

copies are almost blue or purple indicating lack of yellow...

i also changed development drive and motors no luck still the same...

finally changed hv unit and no luck...


i am stuck and suffer from a mega headache with this problem....

oh yes i also tried printheads stilll the same...


many thx for your response

[albasoul06]

Replace CL3 (# 9322 1300 21) or PRCB

[copiers4africa]

thnx the prcb has been replaced ..



which clutch are u referring too when u say clucth cl3 (9322 1300 21)

where would this clucth be i.e development drive or...

[acusso1234]

Take out the belt and look at the roller under the Yellow. Probably it is damaged and don't move during the process. I've changet TBU twice for this in the past.