Brother 1920CN - Color Inkjet - Fax, Service Manual

Page: 47 / 286

IV - 1
1. DISASSEMBLY/REASSEMBLY
n n
Safety Precautions
To prevent the creation of secondary problems by mishandling, observe the following precautions
during maintenance work.
(1) Unplug the power cord from the power outlet before accessing parts or units inside the
machine. 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 wrist watches and rings before working on the printer. A
reflected beam, though invisible, can permanently damage your eyes.
(3) If the machine has been printing, allow the heat-fixing unit (inside this unit is a red-colored
heater roller) sufficient time to cool down before starting maintenance jobs. 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 feed roller ASSY or document 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 machine 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.
(9) Be sure to reinsert self-tapping screws correctly, if removed. Unless otherwise specified,
tighten screws to the following torque values:
Taptite, bind B and cup B M3: 0.7 N
•
m
M4: 0.8 N
•
m
Taptite, cup S M3: 0.8 N
•
m
Other screws M3: 0.7 N
•
m
M4: 0.8 N
•
m
(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 Section 2 in
this chapter.)
(12) After repairs, check not only the repaired portion but also that the connectors and other
related portions function properly before operation checks.