Brother DCP-7090 Service Manual page 109

 Error code BB00
A white level not within the standard was scanned when function code 55 was executed.
Step
Dirt on the second side
1
document hold
2 Dirt on the white tape
3 First side CIS unit failure
4 Second side CIS unit failure
Second side document hold
5
failure
6 White tape failure
7 Main PCB failure
 Error code BC00
When scanning the fax, white or black correction data for the second side CIS was not within
the correct range (second time).
Step
Incorrect correction data for
1
second side CIS unit
Dirt on the white tape on the
2
second side document hold
Damaged second side CIS flat
3
cable
4 Second side CIS unit failure
5 White tape failure
6 Main PCB failure
 Error code BD00
A black level not within the standard was scanned when function code 55 was executed.
Step
Dirt on the second side
1
document hold
2 Dirt on the white tape
3 First side CIS unit failure
4 Second side CIS unit failure
Second side document hold
5
failure
6 White tape failure
7 Main PCB failure
Cause
Cause
Cause
2-69
Remedy
Clean the second side document hold.
Clean the white tape.
Replace the first side CIS unit.
Replace the second side CIS unit.
Replace the ADF unit.
Replace the document scanner unit.
Replace the main PCB ASSY.
Remedy
Execute "Acquire white level data
(Function code 55)".
Clean the white tape on the second side
document hold.
Replace the second side CIS flat cable.
Replace the second side CIS unit.
Replace the ADF unit.
Replace the main PCB ASSY.
Remedy
Clean the second side document hold.
Clean the white tape.
Replace the first side CIS unit.
Replace the second side CIS unit.
Replace the ADF unit.
Replace the document scanner unit.
Replace the main PCB ASSY.
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