Pro C500 problem with yellow (fading)

[acidufo]

Hey everybody,

I`ve got a KM PRO C500 and recently changed the Y developer an toner cartridge. It printed quite well for a while but today the bastard surprised me with this.....attached images.
Yellow is simply missing and that line came up too. Any suggestions?
I`ve added more developer thinking that might solve the problems, also changed the cartridge with the old one, but no.... Yellow is more like orange...too many Magenta and I don`t know what to do next.

[bachirabouzeid]

it seems that you have to clean the yellow developing unit because you have 2 white lines, then you have to adjust the printer gamma offset adj

[Utility] -> [Administrator Setting] -> [System Setting] -> [Expert Adjustment] -> [Quality Adjustment] -> [Printer Gamma Offset Adj.
probably you have to decrease the magenta value
after that make gamma adj