Lexmark W820 Service Manual page 163

Step Actions and Questions
4 IMAGE TRANSFER INSPECTION
Remove the Rear Cover.
Generate a Test Print and switch OFF printer power halfway
through the print cycle.
Open the Left Upper Cover.
Open the Drum Shutter.
Hand rotate (counterclockwise) the Main Drive Motor to
advance the Drum far enough so you can see the developed
image area on the Drum before it reached Transfer.
Before Transfer was the toner image on the drum normal
and without vertical streaks, but there are vertical streaks
on the paper after Transfer?
5 FUSER INSPECTION
Generate another Test Print and switch OFF printer power
when the print is halfway through the Fuser.
Open the Left Upper Cover.
Examine the paper areas before the image enters the Fuser
and after the image exits the Fuser.
Is the image on the paper normal before it enters the
Fuser, but there are vertical streaks visible when it exits
the Fuser?
6 FUSER ASSEMBLY REPLACEMENT
Replace the "Fuser Assembly" on page
Run a half dozen Test Prints.
Are the vertical streaks gone?
7 The following printer FRUs and areas are associated with this
specific problem. One or more of these FRUs or areas may
have failed partially or completely. If you cannot isolate this
problem using the steps in this Service Check, replace each
FRU or troubleshoot each area listed below, one at a time, until
you isolate and solve the problem.
• Refer to the wiring diagrams and check for a broken wire or
loose connection between FRUs in the Xerographic sections of
the printer.
• I/O PWB - Go to
4025-XXX
"I/O PWB" on page 4-89.
Yes
Go to step 5
Go to step 6
Problem
solved
4-65.
No
Replace the
"BTR
Assembly"
on page 4-61
Replace the
"Printhead
Assembly"
on page 4-57
Go to step 7
Diagnostic Information
2-67