Canon D78-5132, Service Manual

Page: 83 / 134

Part 4: Troubleshooting
4-5
5V_SW.
S6V 15V 5V
7
P.F.C.
control
P.F.C.
Abnormal temperature detection inside
of the projector.
Abnormal temperature detection on
the Main board.
Interlock switch
TSW611
LAMP
CB2
CB2
K8CC-1
K8CC-4
CB1
LAMP.DET
LAMP
SW.
When an abnormal
temperature is detected at
the periphery of lamp
driver circuit, the voltage of
this line comes HIGH.
LAMP BALLAST UNIT
Switching power
supply
Check signal at pin 5
of T651
Abnormal temperature
detection at the
periphery of P.F.C.
circuit
Check that the thermal switch (TSW611)
is operating.
If temperature at peraiphery of P.F.C.
circuit reaches 95˚C, TSW611 turns on.
TSW611 -- OPEN: Normal
Q671, Q681
IC2641 ~ IC2681
Check that the FAN DRIVE
signal at pin 19 of IC1804 is
correct.
H : Power ON
Is projection of lamp cover inside
broken or not fitting correctry ?
Check the interlock switch (SW904)
and lamp cover.
SW904 -- OPEN : abnormal
Is thermal switch (SW902) operating ?
If peripheral temperatures at the lamp
house reaches 100˚C, the thermal
switch turns off.
SW902 -- OPEN: abnormal
(Power-On: H)
(Error: H)
F
A
N
_
D
R
IV
E
F
A
N
C
O
N
T
1
LAMP_BST_SW
LAMP_SW
LAMP_ERR
IC2831
PSDA
PSDA
IC2832
TEMP.
SENSOR
TEMP.
SENSOR
TEMP. BOARD
IIC BUS
SW902
SW904