Canon D78-5132, Service Manual

Page: 79 / 134

1. TROUBLESHOOTING
1.1 No Power
1) Periphery of chassis
1. Is fuse (F601) blown?
Fuse may be opened when either the LAMP indicator or the READY indicator isn't
Illuminated. Check the fuse.
• For continued safety, replace with a fuse of the same type.
TYPE T4.0AH 250V FUSE. (LITTLE FUSE INC. TYPE 215004)
2. Is projection of lamp cover inside broken or not fitting?
Check the INTER LOCK switch(SW904) and lamp cover.
SW904 ...............................................OPEN : abnormal
3. Is thermal switch(SW902) operating?
If temperatures periphery of lamp house reaches 100˚C, the thermal switch will be
turned off automatically.
SW902 ...............................................OPEN : abnormal
4. Is the WARNING TEMP. indicator flashing ? The thermal sensor IC (IC2832) on the
Temp. board or IC2831 on the main board may detect the abnormal temperature
inside of the projector. If one of these ICs detects the abnormal temperature, this
projector will be turned off automatically.
2) Power board
1. Are the LAMP indicator(red) and READY indicator(green) light?
If the LAMP and READY indicators do not illuminated, check the primary circuit and
S6V of standby power supply circuit.
2. Check that the LAMP BST-SW signal is correct.
Pin 12 of K6K .....................................H : ON
3. Check that the 5V_SW signal is correct.
Pin 11 of K6K .....................................H : ON
4. Check that the POWER FAIL signal is correct.
Pin 13 of K6K .....................................L : abnormal
5. Is thermal switch(TSW611) operating?
If temperatures periphery of P.F.C. circuit reaches 95˚C, the thermal switch will be
turned on automatically.
TSW611 .............................................SHORT : abnormal
6. Check the signal at pin 5 of T651. (Switching power IC output signal)
Part 4: Troubleshooting
4-1