Brother MFC640CW Service Manual page 267

Error Code
(Hex)
B0 Not used.
B1 Dark level offset data
level error for scanning.
(Not used.)
B2 Gain control data level
error for scanning.
(Not used.)
B3 Scan area left edge
detection error.
(Not used.)
B4 Scan area right edge
detection error.
(Not used.)
B5 Horizontal scanning edge
reduction detection error
in scanning area setting
(Not used.)
B6 Horizontal scanning edge
enlargement detection
error in scanning area
setting
(Not used.)
B7 A/D converter reference
voltage error (at High
level).
(Not used.)
B8 A/D converter reference
voltage error (at Low
level).
(Not used.)
B9 Light emission intensity
error of the LED array
(Exceeding the upper
limit).
Symptom
9 - 1 6
Probable Cause
CIS defective
Main PCB defective
CIS defective
Main PCB defective
CIS defective
White film stained in
the scanner unit.
CIS defective
White film stained in
the scanner unit.
-
-
Main PCB defective
Main PCB defective
CIS defective
Main PCB defective
Solution
Replace the scanner
cover (scanner unit).
Replace the main PCB.
Replace the scanner
cover (scanner unit).
Replace the main PCB.
Replace the scanner
cover (scanner unit).
Replace the scanner
cover (scanner unit).
Replace the scanner
cover (scanner unit).
Replace the scanner
cover (scanner unit).
-
-
Replace the main PCB.
Replace the main PCB.
Replace the scanner
cover (scanner unit).
Replace the main PCB.
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