Fuse Explanation - Brother LZ2-B855E Service Manual

8-3. Fuse explanation

Note
If a component on a PCB is damaged, a fuse may blow again immediately even when it has been replaced.
When replacing a fuse, be sure to use the specified ones listed below.
Power supply circuit board
Connector of connecting the
power switch
Resistor assy
< If fuse F1 or fuse F2 is blown >
Problem : The 7 segment LED is not indicated, and nothing operates.
Before replacing a fuse, separate connectors (connector of connecting the power switch and CN2 or CN3 or CN4) on the
power supply circuit board and measure the resistance as shown in the table.
Connector's pin No. of
connecting the power
switch
1 and 3
If the resistances are good, replace the blown fuses. (Name of parts of the fuse F1 and the fuse F2 - "FUSE, 15A#2" CODE
- 218469001)
If the resistances are no good, replace the power supply circuit board.
< If fuse F3 or fuse F4 is blown >
Replace the power supply circuit board. (There is a possibility that the component on the power supply circuit board is
damaged.)
4
3
2
1
F4
CN2 connector's pin No.
3
3
-
1 and 2
1
1
F3
CN7
CN6
CN5
CN1
No good resistance
1
Short-circuit (a little Ω)
2
-
Except ∞
1
2
LZ2-B855E,B856E
8. ELECTRIC COMPONENTS
F1
4
F2
3
2
CN4 CN2
1
CN3
1147S
8-04