Main Pcb - Brother MFC5490CN Service Manual

6.1.9

Main PCB

Caution: Before replacing the main PCB, make sure that the machine information has been
backed up in an external memory. Failure to back up the machine information requires the ink
absorber box and flushing box to be replaced after replacement of the main PCB.
For detailed backup and restoration procedures, refer to
Machine Information (Function code 46)."
Caution: Before accessing the main PCB, make sure that the power cord is unplugged from the
electrical outlet and the telephone line is disconnected; otherwise, an electric shock could occur.
Caution: At the time of removal of the main PCB, untightening screws should be preceded by
disconnection of the harnesses and flat cables, and at the time of installation, connection of the
harnesses and flat cables, by tightening of screws. Observing this sequence prevents harnesses
and flat cables from getting crushed or damaged by screws or screwdrivers.
(1) Disconnect the following harnesses and flat cables from the main PCB.
Caution: Do not remove the screws from the main PCB before disconnecting harnesses
and flat cables.
Note: After disconnecting the flat cables, check that each cable is not damaged at its end or
short-circuited. When connecting the flat cables, do not insert them at an angle. After
insertion, check again that they are not at an angle.
- Ink cartridge detection sensor harness (7-wire)
- Ink empty sensor harness (9-wire)
- ASF* encoder harness (4-wire) (*Auto Sheet Feeder)
- Purge cam switch harness (2-wire)
- Cap lift cam switch harness (2-wire)
- Power supply harness (5-wire)
- PF encoder/registration sensor harness (7-wire)
- Paper feed motor harness (2-wire)
- ASF* motor harness (2-wire)
- Carriage motor harness (2-wire)
- Head flat cable 1 (12-wire)
- Head flat cable 2 (11-wire)
- Head flat cable 3 (10-wire)
Carriage motor harness
(2-wire)
(Document sensor PCB harness)
(5-wire)
(ADF motor harness)
(4-wire)
(CIS motor harness)
(4-wire)
ASF motor harness
(2-wire)
Paper feed motor
harness
(2-wire)
PF encoder/
registration
sensor harness
(7-wire)
Power supply
harness
(5-wire)
For debugging at the factory.
Do not disturb it.
Main-MJ (LINE) harness
(2-wire, yellow)
Main PCB
(Panel-main harness)
(Speaker harness)
(5-wire)
(2-wire)
Chapter 9, Section 9.4.10 "Backup of
Main-MJ (EXT) harness
(2-wire, black)
Head flat cable 3 (10-wire)
Head flat cable 1 (12-wire)
Head flat cable 2 (11-wire)
(CIS flat cable) (12-wire)
(Main_PCB_BHL9_A4_1)
6-34
(USB interface)
(LAN interface)
Cap lift cam
switch harness
(2-wire)
Purge cam
switch harness
(2-wire)
ASF encoder
harness
(4-wire)
Ink empty
sensor harness
(9-wire)
Ink cartridge
detection sensor
harness
(7-wire)
Confidential