Lamp Abnormality - Sanyo PLC-XF30 Service Manual

LAMP ABNORMALITY -1

System Control
NOTE :
The lamp emits light through arc discharge. To initiate arc discharge, dielectric breakdown must
occur between the lamp electrodes. The high-voltage pulse generator generates and applies high-
voltage pulses with peak values of about 20kV between the lamp electrodes in order to generate
glow discharge. This in turn results in dielectric breakdown between the electrodes, causing a shift
from glow discharge to arc discharge.
After projector turned on, 30 seconds are required until the light output stabilizes. After the projector
is turned off, the cooling fan operates for 90 seconds to cool down the lamp and reduce gas pres-
sure inside the lamp. During this "cooling down" period, the projector cannot be turned on.
Hot circuit
INTERLOCK SW
FUSE
F901
AC-INPUT
SW902
Isn't the lamp cover of a projec-
tor removed?
When it is removed, the projector
cannot be turned on.
FANS
Is the lamp cover attached correctly?
And has not the boss(Inner side of the
FANS
lamp cover) broken?
Check the boss and the Interlock switch
(SW902).
SW902 -- open : Abnormality
NOTE :
The ready (green) LED indicates lamp monitor
operation as follows:
LED off: Lamp is being cooled.
LED on: Lamp is being lit or already cooled down.
LAMP
REPLACE
WARNING
TEMP.
READY
LAMP
INDICATORS
ously, CPU judges the state to be abnormal.
projector compulsorily. And CPU sets up the cooling time for
90 seconds.
Troubleshooting
ASS'Y POWER
AC
DC out
16V /9V /6.25V /-6V
Always
DC out
POWER
SWITCH
CONTROL Switched
FAN
ON/OFF CONTROL
I / O
EXPANDER
SUB POWER
CPU IC801
and
I / O
EXPANDER
IC1831
CPU : ---- Lamp monitor operation.----
CPU performs an input check by the lamp monitor pin.
When the "H" signal continues 1 second or more continu-
When it has detected abnormal condition, CPU turns off a
The projector cannot be turned on during a cooling time.
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Refer to next page
TEMP. SW
LAMP
PFC units
BALLAST units
RL-12V
CHECK !
CIRCUIT
CHECK !
CHECK !
TEMP. SW
LAMP
assemblies
+B
THERMAL-Switches
for LAMP assemblies
NOTE :
The lamp-ballast-unit controls the power supply
to the lamp to maintain and stabilize the arc dis-
charge, keeping illumination at a constant level.
If the lamp does not light or is extinguished sud-
denly, the "Hi" signal is fed to I/O expander and
CPU. (Lamp monitor signal)
RESET HAND OPERATED RESET
RESET
SWITCH for CPU
FOR FAN CONTROL
TEMP.
IIC-SCL & SDA
IC5801
SENSOR
PRESSURE FOR FAN CONTROL
PRESSURE SENSOR
IC886
SENSOR
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