Disassembly/Reassembly; Safety Precautions - Brother MFC620CN Service Manual

5.1 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 machine.
(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
such as aluminum foil.
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
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.
5-1
Section 5.2 in
Confidential