Temperature Abnormality - Sanyo PLC-EF30 Service Manual

TEMPERATURE ABNORMALITY -1

System Control
NOTE : Temperature monitor operation.
■ The temperature monitor system is provided to prevents damage of optical components (the
LCD panel and polarization film etc.) inside a projector from overheat. Two protection systems
are provided. Each system operation as follows ;
■ Temperature monitor -1.
--- To control the driving power of the cooling fans. ----
CPU checks the temperature and atmospheric pressure inside a projector. And CPU controls the
drive power of the cooling fans so the temperature inside the projector is maintained to normal
temperature.
---- To shut down the projector. ---
CPU checks temperature of LCD panel periphery and inhalation air(IC5801). If each part temper-
ature reaches to abnormal temperature, CPU will turn off a projector, and will blink TEMPERA-
Hot circuit
INTERLOCK SW
FUSE
F901
AC-INPUT
SW902
CHECK Fan
FANS
FANS
CHECK !
*
NOTE : TEMP. MONITOR LED OPERATION
■ The red LED indicates temperature monitor operation as follows:
LED off: Normal temperature.
LED flashes in 0.6 second interval: Abnormality temperature.
Doesn't the temperature warn-
LAMP
ing indicator (red) blink?
REPLACE
WARNING
The projector is turned off when TEMP.
the temperature around the LCD
READY
panel reaches 46 - 48 degrees.
And a temperature warning indi-
LAMP
cator blinks.
INDICATORS
NOTE : CPU OPERATION
■ CPU (IC801) performs an input check by the IIC-SDA
■ When it has detected abnormal condition, CPU turns off
Troubleshooting
TURE WARNING indicator at intervals of 0.6 seconds. Cooling fans operate until temperature
returns to normal. Indicator will stop blink, if temperature returns to normal.
■ Temperature monitor -2. --- (Temperature check of lamps) . ----
Temperature switches are arranged near each lamp. Temperature switches will operate, if tem-
perature reaches 90 - 100 degrees.
When temperature switches have operated, lamp ballast units will be shut down, then a projec-
tor will be turned off.
Note. CPU does not check operation of temperature switches. Therefore, when temperature
switches have operated and a projector has shut down, TEMPERATURE-WARNING indicator
does not blink.
ASS'Y POWER
AC
DC out
Refer to next
16V /9V /6.25V /-6V
page but one
Always
DC out
POWER
SWITCH
CONTROL Switched
FAN
ON/OFF CONTROL
I / O
EXPANDER
SUB POWER
CHECK !
CPU IC801
and
I / O
EXPANDER
IC1831
signal pin.
the projector compulsorily. Cooling fans operate until
temperature returns to normal. Moreover, a projector
cannot be turned on during this period.
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Temperature sensors location can see it on "protections"( page-5).
Has not the temperature switch
Has not the temperature
operated?
switch operated?
When the temperature around a
If the temperature around FET
lamp driver reaches 85 degrees, unit
reaches 85 degrees, a PFC
lamp ballast will be shut down and a
circuit will be shut down.
lamp monitor signal changes from L
to H.
TEMP. SW
LAMP
PFC units
BALLAST units
RL-12V
CIRCUIT
❐
Projector shut down.
❐
Cooling fans drive power control.
CPU performs temperature check
around the LCD panel using tempera-
CPU checks the temperature and atmo-
ture sensor IC2541 (B-side of assembly
spheric pressure inside a projector. And
main). If this temperature reaches 47
CPU controls the drive power of the cool-
degrees, CPU will turn off a projector,
ing fans so the temperature inside the pro-
and will blink TEMPERATURE WARN-
jector is maintained to normal temperature.
ING indicator at intervals of 0.6 sec-
onds.
TEMP. SW
LAMP
assemblies
+B
THERMAL-Switches
for LAMP assemblies
Have not the temperature switches operated?
Temperature switches are arranged near each lamp.
Temperature switches will operate, if temperature reach-
es 90 - 100 degrees.
When temperature switches have operated, lamp ballast
units will be shut down, then a projector will be turned off.
■ Note :
CPU does not check operation of temperature switches.
Therefore, when temperature switches have operated
and a projector has shut down, TEMPERATURE-WARN-
ING indicator does not blink.
RESET HAND OPERATED RESET
RESET
SWITCH for CPU
FOR FAN CONTROL
TEMP.
IIC-SCL & SDA
IC5801
SENSOR
FOR FAN CONTROL
PRESSURE
PRESSURE SENSOR
SENSOR IC886
ABNORMAL TEMP. DETECT
TEMP.
IIC-SCL & SDA
IC2541
SENSOR
TEMP. SENSOR
TEMP. ABNORMAL TEMP. DETECT
SENSOR
PTH901
The PTH901 does not exist
in some particular models.
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SW3801