Brother DCP-L5500D Service Manual page 156

 White streaks
Step
1 Dirt inside of scanner glass
Dirt inside of first side/second side
2
scanner glass strip
3 First or second side CIS unit failure Replace the first or second side CIS unit.
4 Scratch on scanner glass
Scratch on second side scanner
5
glass strip
 Partially shaded
Step
1 Dirt inside of scanner glass
2 Deformed document sponge
 Fully tinged
Step
Incorrect white level correction data Execute "Acquire white level data
1
2 First or second side CIS unit failure Replace the first or second side CIS unit.
3 Main PCB failure
<User Check>
• Clean the scanner glass or first side/second side scanner glass
strip.
• Clean the document hold.
Cause
<User Check>
• Clean the scanner glass.
Cause
<User Check>
• Clean the scanner glass or first side/second side
scanner glass strip.
Cause
2-121
Remedy
Clean the inside of the scanner glass.
Clean the inside of the first side/second side
scanner glass strip.
Replace the document scanner unit.
Replace the ADF unit.
Remedy
Clean the inside of scanner glass.
Replace the document scanner unit.
Remedy
code: 55)".
Replace the main PCB ASSY.
(function
Confidential