5-22 Phaser 6128MFP Service Manual
Print-Quality Troubleshooting
Horizontal Stripes
There are black lines running parallel with the leading edge of the print, 
perpendicular to the direction of the paper travel.
Initial Actions
• Check the paper transfer path.
• Ensure there are no debris on the transfer path.
Allow the Fuser to cool before starting the procedure.
Troubleshooting Reference Table
Applicable Notes Example Print
■ Laser Unit Kit (PL4.1.99)
■ Imaging Unit (PL4.1.21)
■ Toner Cartridge K (PL5.1.21)
■ Toner Cartridge C (PL5.1.22)
■ Toner Cartridge M (PL5.1.23)
■ Toner Cartridge Y (PL5.1.24)
■ Fuser (PL6.1.1)
■ Transfer Belt (PL6.1.7)
■ IP Board (PL10.6.6)
■ MCU Board (PL10.7.7)
Troubleshooting Procedure Table
Step Actions and Questions Yes No
1 Run the Contamination Check test 
print: Service Mode > Test Print > 
Contamination Chk
Compare any horizontal dropout 
bands with the Pitch Chart 
(page 5-51). 
Do any of the horizontal bands 
match the chart?
Replace the 
corresponding 
parts.
Go to step 2.
2 Check the Transfer Belt high-voltage 
connections..
Are the contacts on the Transfer Belt 
and springs damaged or dirty?
Clean or 
replace the 
Transfer Belt 
contacts or 
spring(s).
Go to step 3.