Brother MFC640CW Service Manual page 266

Error Code
(Hex)
A4 50% or more faulty of
white level data.
(Not used.)
A5 FAX scanning failure (1st
time)
A6 FAX scanning failure
(retry)
A7 Mismatch between the CIS
type and EEPROM data
A8-AB Not used.
AC Less than 50% faulty of
white level data.
(Not used.)
AD-AE Not used.
AF CIS positioning error.
Symptom
9 - 1 5
Probable Cause
CIS flat cable not
connected properly
CIS defective
Main PCB defective
CIS defective
White-level reference
film stained in the
scanner cover
Main PCB defective
Scanner cover containing
the improper CIS type
mounted at repair
CIS defective
Main PCB defective
CIS flat cable broken
or not connected
CIS motor harness not
connected properly
CIS motor defective
Drive unit defective
CIS defective
Main PCB defective
Solution
Correct the connection.
Replace the scanner
cover (scanner unit).
Replace the main PCB.
Replace the scanner
cover (scanner unit).
Replace the main PCB.
Check the CIS type and
write it to the EEPROM
by using maintenance-
mode function code 59.
(Refer to Chapter 8,
Section 8.4.12.)
Replace the scanner
cover (scanner unit).
Replace the main PCB.
Correct the cable
connection.
Replace the scanner
cover (scanner unit).
Correct the harness
connection.
Replace the scanner
cover (scanner unit).
Replace the scanner
cover (scanner unit).
Replace the scanner
cover (scanner unit).
Replace the main PCB.
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