Cause

Developer/toner mixture fault (C-2421 Yellow, C-2422 Magenta, C-2423 Cyan, C-2424 Black)

Resolution

Watch the video showing how to clear clogged toner in the toner hopper

Run toner density revert...

1. Power the machine OFF from the main switch leaving the sub switch ON.
2. Turn main power switch ON while pressing the Utility/Counter key. Keep holding it till the comes up in Service mode.
3. -02 process adjustment
4. -02 drum peculiarity
5. -06 toner density revert select "All On"
6. -select start (When the machine gets the values for each colour, the values need to be in around 1.26, as near as possible, keep pressing start until you get the values for each colour as near as possible, doesn’t have to be exact)
7. -when process completes, return out
8. -02 gamma automatic adjust (wait until process completes)
9. Exit out of service mode and go into adjustment at the bottom of the screen.
10. Go to adjustments at the bottom of the screen - Select Operator Execute Adjust - Select toner refresh - exit to print screen