Color Laserjet 4550 fade colors

[da07228]

Hi, I have a user with a clj 4550 that's printing very fade colors. I've tried replacing some parts (transfer roller, transfer belt, drum, and toner cartridges) with the same results. Would a dirty density or toner level sensor cause this behavior?.

Thanks for your help.

[Brian]

A density sensor malfunction can cause faded print-outs, the toner level sensor can't.
The laser unit can cause this problem too.