4WK7-042
Streaks that are perpendicular to the direction of feed appear in the printout
The intermediate transfer belt is warped. Adjust the Primary Transfer Voltage (the voltage that transfers toner image from the Intermediate Transfer Belt to the paper).
← Feeding Direction
Remedy
If you have not used your machine for a long period of time, the intermediate transfer belt may become warped. If this happens, clean inside the main unit several times.
IMPORTANT
This function is displayed only if the settings are made available by your local authorized Canon dealer. Even if this function is displayed, do not allow anyone to change the settings except for the system manager. For more information on changing the settings, contact your local authorized Canon dealer.
Press 
→ [Preferences] → [Paper Settings] → [Paper Type Management Settings] and then select the paper type to edit from the list → press [Details/Edit] → <Adj. Primary Transfer Voltage> → [Change] → [-] to change the primary voltage that transfers the black toner → press [OK] to decrease the primary voltage.
→ [Preferences] → [Paper Settings] → [Paper Type Management Settings] and then select the paper type to edit from the list → press [Details/Edit] → <Adj. Primary Transfer Voltage> → [Change] → [-] to change the primary voltage that transfers the black toner → press [OK] to decrease the primary voltage.
"Paper Type Management" > "Adjusting the Primary Transfer Voltage" in the User's Guide