Brother DCP-6690CW, Service Manual, Page: 182 / 506

6-1 Confidential
6.1 DISASSEMBLY/REASSEMBLY
„
Safety Precautions
To prevent the creation of secondary problems by mishandling, observe the following
precautions during maintenance work.
(1) Before replacing parts or units, unplug the power cord and telephone line*.
In particular, when having access to the power supply inside the machine, make sure that
the power cord is unplugged from the electrical outlet; when having access to the main
PCB or MJ PCB*, make sure that both the power cord and telephone line* are unplugged
from the electrical outlet.
*
For MFC only
(2) Be careful not to lose screws, washers, or other parts removed for parts replacement.
(3) When using soldering irons and other heat-generating tools, take care not to damage the
resin parts such as wires, PCBs, and covers.
(4) Static electricity charged in your body may damage electronic parts.
Before handling the PCBs, touch a metal portion of the machine to discharge static
electricity charged in your body. When transporting PCBs, be sure to wrap them in
conductive sheets.
When replacing the head/carriage unit, put on a grounding wrist band and perform the job
on a static mat. Also take care not to touch the conductor sections on the flat cables.
(5) Be sure to reinsert self-tapping screws correctly, if removed.
(6) Tighten screws to the torque values listed on the next page.
(7) When connecting or disconnecting cable connectors, hold the connector bodies not the
wires. If the connector has a lock, always slide the connector lock to unlock it.
(8) Before reassembly, apply the specified lubricant to the specified points. (Refer to Section
6.2 in this chapter.)
(9) After repairs, check not only the repaired portion but also that the connectors and other
related portions function properly before operation checks.
(10) Once the head/carriage unit prints, it will start head locking operation after five seconds
from the end of printing. The head locking operation will take 5 to 10 seconds. NEVER
unplug the power cord before the machine completes the head locking operation; doing so
will make the head/carriage unit unusable and require replacement with a new head/
carriage unit.
When you receive the machine from the user or when you pack it for sending it back to the
user, check the head locking state.
(11) After disconnecting flat cables, check that each cable is not damaged at its end or short-
circuited.
When connecting flat cables, do not insert them at an angle. After insertion, check again
that the cables are not at an angle.
(12)
CAUTION
DOUBLE POLE/NEUTRAL FUSING