Konica-Minolta bizhub C3350

How to identify problematic part

• This chapter is divided into two parts: “Initial check items” and “Troubleshooting procedure by a particular image quality problem.”
• When an image quality problem occurs, first go through the "Initial check items" and, if the cause is yet to be identified, go to "Troubleshooting procedure by a particular image quality problem."

Initial check items

• Let the machine produce a test print and determine whether the image problem is attributable to the scanner or printer system.
• Evaluation procedure

Action	Result	Cause
From [Service Mode], select [Test Mode] -> [Gradation Pattern], and produce a test print. Is image problem evident?	YES	Printer
	NO	Scanner

Printer monocolor: white lines, white bands, colored lines and colored bands in sub scan direction

Troubleshooting procedure

Step	Section	Check item	Result	Action
1	Image check	A white line or black line in sub scan direction is sharp.	YES	Clean the electrostatic charger wire.
3	Imaging unit	The surface of the PC drum is scratched.	YES	Replace the imaging unit.
4		Dirty on the outside.	YES	Clean.
5		Contact terminals make good connection between each imaging unit and machine.	NO	Clean contact terminals.
6		Developing bias contact terminal makes good connection.	NO	Clean contact terminal and check terminal position.
7	PH unit	The surface of the PH window is dirty.	YES	Clean with cleaning jig.
8		The problem has been eliminated through the checks of steps up to 7.	NO	• Replace the transfer belt unit. • Replace the PH unit.

Printer monocolor: white lines, white bands, colored lines and colored bands in main scan direction

Troubleshooting procedure

Step	Section	Check item	Result	Action
1	Image check	A white line or black line in main scan direction is sharp.	NO	Clean the electrostatic charger wire.
2	Imaging unit	The surface of the PC drum is scratched.	YES	Replace the imaging unit.
3		Dirty on the outside.	YES	Clean.
4		Contact terminals make good connection between each imaging unit and machine.	NO	Clean contact terminals.
5		Developing bias contact terminal makes good connection.	NO	Clean contact terminal and check terminal position.
6	PH unit	The surface of the PH window is dirty.	YES	Clean with cleaning jig.
7		The problem has been eliminated through the checks of steps up to 6.	NO	• Replace the transfer belt unit. • Replace the PH unit.

Printer monocolor: uneven density in sub scan direction

Troubleshooting procedure

Step	Section	Check item	Result	Action
1	Imaging unit	The surface of the PC drum is scratched.	YES	Replace the imaging unit.
2		Dirty on the outside.	YES	Clean.
3	PH unit	The surface of the PH window is dirty.	YES	Clean with cleaning jig.
4	Transfer roller unit	Image transfer roller is installed properly.	NO	Reinstall.
5		Image transfer roller is dirty or scratched.	YES	Replace the transfer roller unit.
6	Transfer belt unit	Is abnormality found in the cam gear?	YES	Replace the transfer belt unit.
7		The problem has been eliminated through the checks of steps up to 7.	NO	• Replace the PH unit. • Replace the printer control board. • Replace the High voltage power supply.