Disassembly/Reassembly; Safety Precautions - Brother IntelliFax-3550 Service Manual

1. DISASSEMBLY/REASSEMBLY

Safety Precautions

To prevent the creation of secondary problems by mishandling, observe the following pre-
cautions during maintenance work.
(1) Always unplug the power cord before replacing parts or units. When having access to
the power supply, be sure to unplug the power cord from the power outlet.
(2) When servicing the optical system of the laser printing unit, be careful not to place
screwdrivers or other reflective objects in the path of the laser beam. Be sure to take
off any personal accessories such as watches and rings before working on the printer.
A reflected beam, though invisible, can permanently damage your eyes.
(3) If the equipment has been printing, allow the fixing unit sufficient time to cool down. It is
HOT!
(4) Be careful not to lose screws, washers, or other parts removed for parts replacement.
(5) Do not remove gears from the document LF roller ASSY or ejection roller ASSY if at all
possible. Once removed, they will become unusable and new gears will have to be put
back in.
(6) When using soldering irons and other heat-generating tools, take care not to damage
the resin parts such as wires, PCBs, and covers.
(7) Before handling the PCBs, touch a metal portion of the equipment to discharge static
electricity; otherwise, the electronic parts may be damaged due to the electricity
charged in your body.
(8) When transporting PCBs, be sure to wrap them in conductive sheets such as aluminum
foil.
WARNING
For the MFC6550MC/7550MC/7650MC/9000/9500 which has a nickel-hydrogen battery
on the main PCB, be sure to remove that battery before transporting the PCB (in alu-
minium foil). Failure to do so may result in a short circuit, overcurrent flow, or fire.
(9) Be sure to reinsert self-tapping screws correctly, if removed.
(10) Tighten screws to the torque values listed on the next page.
(11) 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.
(12) Before reassembly, apply the specified lubricant to the specified points. (Refer to Sec-
tion 2 in this chapter.)
(13) After repairs, check not only the repaired portion but also that the connectors and other
related portions function properly before operation checks.
IV – 1