Temperature Abnormality - Sanyo PDG-DHT100L Service Manual

Troubleshooting

Temperature Abnormality

temperature monitor operation
The temperature monitor system is provided to prevents
damage of optical components inside a projector from
overheat. Two 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 IC881 and IC1381, and it
checks an atmospheric pressure using pressure sen-
sor IC4781. 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 pe-
riphery (IC881), optical parts periphery (IC1381) and
IC4781
PRESS_SENS
PRESS SENSER
IC1381
IIC IIC
TEMP. SENSER
<OPTICAL>
IC301
IC8821
SYSTEM
TEMP. SENSER
CONTROL
<DMD>
IIC
IC8811
TEMP. SENSER
<ROOM>
IC4401
FPGA
BALLAST_AC1
BALLAST_AC2
AC
F901
SW901
FUSE
MAINS
SWITCH
NOTE : SENSORS OPERATION
■ The sensor's operation is as follows:
IC4781 : Pressure sensor For FAN control
IC1381 : Inside air temperature monitor (Optical)
IC8821 : Inside air temperature monitor (DMD)
IC8811 : Inside air temperature monitor (Room)
Temperature sensors location can be seen on
"protections"( page-8).
P.FAIL
IC5201
FPGA
FAN_SW1
IC7801
DAC
FAN_SW2
Power-on: H
IC1801
Stand-by: L
I/O
DC_ON
EXPANDER
K6A
NOISE
FILTER
POWER(AC)
The temperature
switch is operated?
If the temperature
around FET reaches
105 degrees, a PFC cir-
cuit will be shut down.
intake air (IC8811). If each part temperature reach-
es abnormal temperature, the CPU will turn off the
projector, and will blink WARNING TEMP. indicator
at intervals of 0.5 seconds. Cooling fans operate un-
til temperature returns to normal. Indicator will stop
blink, if temperature returns 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 PFC1V 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.
FAN_ERR
FAN
FAN_DAC
CONTROL
PFC12V
IC2601 Lamp Mode Lamp1 Lamp2 Lamp1/2
PFC_ON1 H L
FA7729
PFC_ON2 L H
PFC_ON1
PFC_ON2
ST_SW: L
PFC_ON: H
POWER(DC)
CN6
K6B
PFC1-2
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.
-13-
Check FAN
circuits.
Cooling
Fans
Check the
THERMAL SW
temperature
SW904
H
switches.
H
Opens at 80ªC
THERMAL SW
SW903
LAMP COVER
SW
SW902
X1A X3A
CN4
BALLAST1
CN3
X1B X3B
BALLAST2
LED indicators
When the internal temp
error, the WARNING TEMP.
indicator will be blinking.
When the temperature rises
a b n o r m a l l y a r o u n d t h e
lamps1 or 2, the LAMP indi-
cator is lighting and other
indicators are blinking.
LAMP1
LP901
LAMP2
LP902