Download Print this page

Brother mfc-3420c Service Manual page 7

Hide thumbs


Safety Precautions
To prevent the creation of secondary problems by mishandling, observe the following precautions
during maintenance work.
(1) If you unpack the package sent from the user,
first check that the top edge of the head wiper is
flush with that of the head cap unit before
turning on the machine. If the head wiper
protrudes or is out of place, lightly pull the head
wiper up and towards the head cap unit to
retract it.
(2) Unplug the power cord from the power outlet before replacing parts or units. When having
access to the power supply, be sure to unplug the power cord from the power outlet.
(3) Be careful not to lose screws, washers, or other parts removed for parts replacement.
(4) Do not remove gears from the document feed roller 1 (shown on page 4-14) or document
ejection roller (shown on page 4-20) if at all possible. Once removed, they will become unusable
and new gears will have to be put back in.
(5) When using soldering irons and other heat-generating tools, take care not to damage the resin
parts such as wires, PCBs, and covers.
(6) Before handling the PCBs, touch a metal portion of the machine to discharge static electricity;
otherwise, the electronic parts may be damaged due to the electricity charged in your body.
(7) When transporting PCBs, be sure to wrap them in conductive sheets such as aluminum foil.
(8) Be sure to reinsert self-tapping screws correctly, if removed.
(9) Tighten screws to the torque values listed on the next page.
(10) When connecting or disconnecting cable connectors, hold the connector bodies not the cables. If
the connector has a lock, always slide the connector lock to unlock it.
(11) Before reassembly, apply the specified lubricant to the specified points. (Refer to
(12) After repairs, check not only the repaired portion but also that the connectors and other related
portions function properly before operation checks.
(13) Once the print head 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 print head
unit unusable and require replacement with a new print head 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.
Head wiper
Head cap unit
Section 4.3 in



  Also See for Brother mfc-3420c

  Related Manuals for Brother mfc-3420c

This manual is also suitable for: