KM C227 Vertical Lines when the print has coloured elements on the page

[copytech,mike]

Hi there!
End user is struggling with a KM C227 from some time now. The machine was constantly printing with a magenta hue on all colour pages and the calibration procedures helped a bit whenever the issue was present.
All drums and developing units were changed in the past as they were approaching end of life, but the magenta issue came back after a while and it consumed extra toner. There was also a lot of ejected toner inside the machine.

Now, the machine prints thick vertical lines which seem to be composed of Y, C BK and some M. I've attached a sample print.

Any idea what could be causing the issue? Drums and belt look ok. Possibly the laser unit is dirty?

Moreover, the machine also shows and error C-0202 for Tray 1 . I found some jammed paper in the lift mechanism for Tray 1, but it seems that the motor or sensor is damaged.

Troublesome machine, this one

Nope. Its not gonna be a dirty laser slit glass.

[copytech,mike]

In a nutshell the copier is writing to the drum when its not suppose to be is a clue.

[Oystercopy]

About the copy quality errors, I didn't see anyone ask whether there might be generic toner in the machine?
OC

[Synthohol]

Because this thread is 4 years old.
Necroposting.
Likely settled a long long time ago.