Canon D78-5132, Service Manual

Page: 36 / 134

2. CIRCUIT PROTECTIONS
This projector is equipped with the following circuit protections to operate in safety. If
the abnormality occurs inside the projector, it will automatically turn off by operating
one of the following protection circuits.
2.1 Fuse
The fuse is located inside of the projector. When
either the LAMP indicator or the READY
indicator is not illuminated, fuse may be
opened. Check the fuse as following steps.
It should be used the specified fuse as follows;
[How to replace the fuse]
1. Remove the cabinet top and main board
following to “Mechanical Disassemblies”.
2. Remove a screw and the line filter cover
upward.
3. Remove the fuse from fuse holder.
To install the fuse, take reversed step in the above.
2.2 Thermal Switch
There is the thermal switch (SW902) inside of
the projector to prevent the internal temperature
from rising abnormally. When the internal
temperature reaches near 100˚C, turn off the AC
main power supply automatically.
The thermal switch is not reset to normal
automatically even if the internal temperature
becomes normal. Reset the thermal switch
following procedure.
Check the resistance between terminals of
thermal switch by using the tester. If it has high
impedance, thermal switch may be in operative.
[How to reset the thermal switch]
1. Remove the cabinet top following to
“Mechanical Disassemblies”.
2. Press the reset button on the thermal switch.
Fuse Part No.: CY2-8376-000
TYPE T4.0AH 250V FUSE
LITTEL FUSE INC. TYPE 215004
Part 2: Repair Information
2-2
Fig. 2-1
Fig. 2-2
Line Filter Cover
Fuse
Line Filter Board
Screw
Reset Button
CAUTION Before press the reset button, disconnect the AC cord from the projector.
Thermal switch (SW902)