Main Pcb - Brother MFC990CW Service Manual

6.1.11 Main PCB

Caution: Before replacement of the main PCB, back up the machine information and user
setting information, referring to
Information (Function code 46) (User-accessible)."
up information to the new PCB. Failure to do so requires replacing also the ink absorber
box and flushing box after replacement of the main PCB.
Caution: Before accessing the main PCB, make sure that the power cord is unplugged from the
electrical outlet and the telephone line (MFC only) 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)
- Hook switch harness (6-wire)
- Charge harness (3-wire)
- Main-MJ (EXT) harness
- Head flat cable 1 (12-wire)
- Head flat cable 2 (11-wire)
- Head flat cable 3 (10-wire)
Chapter 9, Section 9.1.4.13 "Backup of Machine
*1
*2
*3 4
(2-wire* or 6-wire*
*1 For models with handset
*2 For models with cordless handsets
*3 For MFC only
*4 For models destined for countries except Japan
*5 For Japanese models
6-50
After replacement, restore the backed
5
, black)
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