Lexmark W820 Service Manual page 159

Step Actions and Questions
2 CONTROLLER OR HOST SOFTWARE ISOLATION
Generate a Test Print.
Is the test print image normal?
3 EP CARTRIDGE REPLACEMENT
Install a new EP Cartridge.
Is there a normal image on the paper?
4 IMAGE DEVELOPMENT 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.
Is the image on the drum completely developed; with
sharp, black, easily read areas and clear, white areas?
5 ESS PWB REPLACEMENT
Replace the "Controller Board (ESS PWB)" on page
Generate a Test Print.
Is the printed Test Pattern normal?
6 MCU PWB REPLACEMENT
Replace the "Engine Board (MCU PWB)" on page
Generate a Test Print.
Is the printed Test Pattern normal?
7 PRINTHEAD REPLACEMENT
Replace the "Printhead Assembly" on page
Generate a Test Print.
Is the printed Test Pattern normal?
8 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.
• LVPS - Go to
Assembly" on page
• I/O PWB - Go to
• Refer to the wiring diagrams and check for a broken wire or
loose connection between FRUs in the Xerographic sections of
the printer
4025-XXX
"Low Voltage Power Supply (LVPS)
4-82.
"I/O PWB" on page
4-94.
4-92.
4-57.
4-89.
Yes No
Replace the Go to step 3
"Controller
Board (ESS
PWB)" on
page 4-94 or
reload the
host software
Problem Go to step 4
solved
Replace the Go to step 5
"BTR
Assembly"
on page 4-61
Problem Go to step 6
solved
Problem Go to step 7
solved
Problem Go to step 8
solved
Diagnostic Information
2-63