Brother MFC-J5335DW Service Manual page 21

Precautions for Troubleshooting and/or Disassembly/Assembly
Be sure to observe the following warnings and precautions to prevent any secondary troubles
from happening by mishandling the machine during troubleshooting and/or disassembly/
assembly.
Precautions

Be sure to observe the following to prevent any secondary troubles from happening during
troubleshooting and/or disassembly/assembly.
(1) Power codes must be removed from their outlets before starting any removal of covers
and PCBs, adjustments and conductivity test using a tester.
(2) Be careful not to lose screws, washers, or other parts.
(3) Apply grease to the points specified in
(4) When using soldering irons and other heat-generating tools, take care not to damage the
plastic parts such as wires, PCBs, and covers.
(5) When disconnecting the connectors, hold the connector housings. Do not pull the lead wires.
(6) After disconnecting flat cables, check that each cable is not damaged at its end or
shortcircuited.
(7) When connecting flat cables, do not insert them at an angle. After insertion, check again
that the cables are not at an angle.
(8) When connecting or disconnecting harnesses, hold the connector bodies not the cables.
If the connector has a lock, always unlock it.
(9) After repairs, check not only the repaired portion but also that the harnesses are routed
properly. Also check that the other related portions function properly.
(10) 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 PCBs, put on a grounding wrist band and perform the job on a
conductive mat.
Also take care not to touch the conductor sections on the flat cables.
(11) 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 five to ten 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.
(12) If ink gets on your skin or gets into your eyes or mouth, you need the following treatment.
- If ink gets on your skin, wash it off immediately with soap and water.
- If ink gets into your eyes, flush them immediately and thoroughly with water. If left
untreated, the eyes may become bloodshot or mildly inflamed. If you feel any discomfort,
consult a doctor immediately.
- If ink gets into your mouth, immediately spit it out and consult a doctor.
(13) Be sure to observe the warnings.
(14) After completion of reassembly, it is recommended that the dielectric voltage withstand
test and continuity test be conducted.
(15) After repairing the defective section, be sure to check again if the repaired section works
correctly.
Chapter 3
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