Sanyo PDG-DHT8000L - 8000 Lumens, Service Manual

Page: 132 / 242

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Troubleshooting
temperature monitor operation
The temperature monitor system is provided to prevents
damage of optical components inside a projector from
overheat. Three protection systems are provided. Each
system operation as follows :
the temperature monitor -1:
●
to control the air-flow of the cooling fans.
The CPU checks the temperature and atmospheric
pressure inside a projector. It checks a temperature
using temperature sensors IC8821 and IC1381, and it
checks an atmospheric pressure using pressure sen-
sor IC8872. The CPU judges data from sensors and
controls the air flow of the cooling fans so the tem-
perature inside the projector is maintained to normal
temperature.
●
to shut down the projector urgently.
The CPU checks temperature of DMD module periph-
ery (IC8821), optical parts periphery (IC1381) and in-
take air (IC8811). If each part temperature reaches
abnormal temperature, the CPU will turn off the pro-
jector, and will blink WARNING TEMP. indicator at
intervals of 0.5 seconds. Cooling fans operate until
temperature returns to normal. Indicator will stop blink
when the projector turns on after the temperature re-
turns to normal.
the temperature monitor -2 :
●
temperature check of lamps :
Temperature switches (SW903, SW904) are placed
near the lamps. Temperature switches will operate,
if temperature reaches 80ºC. When temperature
switches become open, they cut off PFC12V line, the
power failure "PF_POWER" signal become Low, and
then the CPU will shut down the projector, and the
LAMP indicator is lighting and other indicators are
blinking.
the temperature monitor -3 :
●
temperature check of Peltier device :
Peltier device is provided to cool down the DMD mod-
ule. If the temperature of the Peltier device reaches
50ºC, the projector will shut down as the power error.
NOTE : SENSORS OPERATION
■
The sensor's operation is as follows:
IC8872 : Pressure sensor for FAN control
IC1381 : Inside air temperature monitor (Optical)
IC8821 : Inside air temperature monitor (DMD)
IC8811 : Inside air temperature monitor (Room)
TH901 : Peltier device temperature monitor
LED indicators
When the internal temp
error, the WARNING TEMP.
indicator will be blinking.
When the temperature
rises abnormally around
the lamps1 or 2, the
LAMP indicator is lighting
and other indicators are
blinking.
The temperature
switch is operated?
If the temperature
around FET reaches
105 degrees, a PFC cir-
cuit will be shut down.
The temperature switch is
operated?
When the temperature
around a lamp driver bec-
mes abnormally high, the
lamp ballast will be shut
down and a lamp error sig-
nal changes from L to H.
Temperature sensors location can be seen on
"protections"( page-7).
Temperature Abnormality
AC
F901
FUSE
SW901
MAINS
SWITCH
NOISE
FILTER
K6B
POWER(AC)
K6A
LAMP1
LP901
Cooling
Fans
THERMAL SW
SW904
THERMAL SW
SW903
LAMP COVER
SW
SW902
PFC
BALLAST1
X1A X3A
LAMP2
LP902
BALLAST2
X1B X3B
K16A
K16C
K16B
POWER(DC)
FAN
CONTROL
IC2601
FA7729
IC7801
DAC
IC1801
I/O
EXPANDER
IC4401
FPGA
IC5201
FPGA
IC1381
TEMP. SENSOR
<OPTICAL>
IC8872
PRESS SENSOR
TH901
IC8821
TEMP. SENSOR
<DMD>
IC8811
TEMP. SENSOR
<ROOM>
IC301
SYSTEM
CONTROL
12V
PFC1_SW PFC2_SW
PFC_ON2
PFC_ON
S-6V
SS6V
S16V
S-6V
SS6V S16V
PFC_ON
PFC_ON1
PFC12V
PF_PO
WE
R
DC_ON
PFC_ON SS3.3V
BALLAST_AC2
BALLAST_AC1
P.FAIL
FAN_DAC
FAN_SW1
FAN_SW2
IIC IIC
IIC
FAN_ERR
Lamp Mode Lamp1 Lamp2 Lamp1/2
PFC_ON1 H L H
PFC_ON2 L H H
PFC_ON: H
Power-on: H
Stand-by: L
PRESS_SENS
Check FAN
circuits.
Check the
temperature
switches.
Opens at 80ªC