Temperature Abnormality - Sanyo PLC-WM4500L 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 IC1692, IC1814, IC1816
and it checks an atmospheric pressure using pres-
sure sensor IC886. The CPU judges data from sen-
sors and controls the air flow of the cooling fans so
the temperature inside the projector is maintained to
normal temperature.
SW902 opens at 115ºC.
AC
Error: L
PF_FAN
Error: L
P.FAIL
COOLING
FANS
IC4801
I/O
IC7801
EXPANDER
DAC
<TE7783>
FAN
CONTROL
<M62393>
SW902
THERMAL
PROTECTOR
F601 K6B
FUSE
K6AA
A902
POWER
32
68
154 8
PW_MASTER_SDI
IC301
251 7
PW_MASTER_SDO
SYSTEM
CONTROL
41 9
PW_MASTER_SCK
&
SCAN
343
CONVERTER
<PW392>
281
PRESS_SENS
PW_SDA0/SCL0 PW_SDA0/SCL0
● to shut down the projector urgently.
The CPU checks surrounding temperature of LCD
panel (IC1814), Lamp (IC1816) and intake air (IC1692).
If each part temperature reaches abnormal tempera-
ture, the CPU will turn off the projector, and will blink
WARNING TEMP. indicator. Cooling fans operate until
temperature returns to normal. Indicator will stop blink,
if temperature returns to normal.
the temperature monitor -2 :
● temperature check of lamp :
Thermal protector (SW902) is placed near the lamp.
Thermal protector will operate, if the surrounding tem-
perature reaches 115ºC. When the thermal protector
becomes open, it cuts off the AC line to shut down the
projector immediately.
LOW K6A
RL601
POWER
SB_5V
SUPPLY
S16V
POWER
S6V
SUPPLY
S-6V
K6R
1 29
1 29
K8R
POWER-ON:H
Network Standby: H
LAMP_DC_ON
Eco Standby: L
10
POWER_SW
POWER-ON:H
14
LAMP_SWIN
IC9885
SUB-MICON
15
<LC87F2G>
CHO_TXD
16
CHO_RXD
IC886
PRESS
SENSOR
WARNING TEMP. indicator blinks
The sensor's operation is as follows:
IC886 : Pressure sensor for FAN control
IC1692 : Inside temperature monitor A (room)
IC1816 : Inside temperature monitor B (lamp)
IC1814 : Inside temperature monitor C (panel)
-70-
CJ1
A901
LAMP
BALLAST
CJ2
5 1 4
5 1 4
K8K
K8B
Q1861
3
PF_FAN
2
4
1
1
IC1853
IC1854
INVERTER
1 2
K8E
S3.3V
1
5 3
FILTER_DET
3
IC1816
TEMP
SENSOR B
<LAMP>
K8A
MAIN
K8S
LAMP
LP900
LAMP
COVER SW.
SW901
FILTER SW.
SW1891
IC1692
TEMP
SENSOR A
<ROOM>
IC1814
TEMP
SENSOR C
<PANEL>