Brother MFC640CW Service Manual page 137

(3) Remove screw "a" from the MJ shield and take it off the lower MJ/PS shield.
(4) Remove the power supply shield.
(5) Remove four screws ("c1" through "c4") from the power supply PCB.
(6) Remove screw "b" from the MJ PCB and take it off the lower MJ/PS shield.
Power cord
MJ-main harness
MJ-line harness
MJ/PS shield box
Reassembling Notes
• When securing the power supply PCB, tighten "c1," "c2," "c3," and "c4" screws in this order.
"a"
MJ PCB
"b"
"c3"
"c2"
Power supply PCB
"a": Screw, pan (washer) M3x8DB
"b" and "c1" through "c4": Taptite, cup S M3x6
5 - 5 1
MJ shield
MJ-line harness (2-pin)
MJ-main harness 1 (2-pin)
Lower MJ/PS shield
"c4"
Power supply PCB
"c1"
NOTE: Tighten "c1" through "c4"
screws in this order.
Power supply shield
Confidential