Bizhub C353 Cyan is missing

[Gabriel]

Black, Magenta and Yellow colors are perfect but Cyan isn't printed out.

Machine is clean, no codes, no warnings. It was printing fine
Image units, fuser unit, transfer belt are 50% of its life,

I swapped working Cyan Image unit >No Change<
Cleaned slit glass >No Change<

Running out of ideas. Any help is welcome


PS:
printed Test page is missing Cyan too.
Laser unit block ?
Firmware ?

[copier addict]

There must be a P code. Oil can on display?
If a known good UI doesn't fix it I would try a good HV power supply.

[Gabriel]

copier addict
Thank you for your fast respond.Anything else may cause this issue?
Customer is 70 miles from office (140 miles round trip)


[mrwho]

Had a C250 long ago with exactly the same problem - was the laser unit ever-so-slightly tilted out of position, enough that the laser wouldn't reach the drum.