C3380 White mark on the magenta >>> See Picture

[harnrak]

I have attach the picture of C3380. I clean the Laser Unit already but nothing happen. c3380.JPG

[randall]

Replace the magenta drum unit

[teckat]

Remove Magenta unit and inspect, for any foreign material on developer sleeve

Points to Note When Removing Drum Cartridge
When removing the drum cartridge, make sure that the shutter lever is at the 'Unlock' position.
If removing the drum cartridge from the machine while the shutter lever is not at the 'Unlock' position, and then mounting the cartridge again after shifting the lever to the 'Unlock' position, the shutter of the drum cartridge is not opened properly. Therefore, toner does not get into the drum cartridge from the hopper assembly, and the spilled toner strays within the machine.
If removing the drum cartridge while the shutter lever is not at the 'Unlock' position, put the cartridge back and shift the shutter lever to the 'Unlock' position, and then, remove the
cartridge.

[Canuck]

Try a new drum unit. Run a TEST page 5,set y,c and k to zero,magenta to 255.If the drum don't fix it,take a look at internal primary transfer roll for magenta