Sanyo PLV-Z4 Service Manual page 73

● Description of System control circuit
Power saving system control
When the projector is standby mode, IC301(Main CPU) is not working and IC4801(Sub CPU) is only working for
saving energy. IC4801 is working for power management at standby mode and lamp control at normal mode.
(Refer to "Power supply circuit" for detail)
Remote control
R/C signal is sent to pin 52 of IC301(Main CPU) and also sent to pin 22 of IC4801(Sub CPU). R/C signal is
received by IC4801 only at standby mode.
Thermal switch
There is the thermal switch (SW902) above the lamp holder to prevent the internal abnormal temperature rising. If
the internal temperature reaches near 90°C, the switch will be opened and LAMP_SW signal will be shut off auto-
matically and the lamp operation will be stopped.
Remark;
The thermal switch is not reset to normal automatically even if the internal temperature becomes normal,
so in this case you have to reset it manually.
Lamp cover switch
If the lamp cover is not fixed securely, the lamp cover switch(SW8803) will be open, and LAMP_SW signal will be
shut off automatically and the lamp operation will be stopped.
Temperature sensor
The projector provides the temperature sensors "TH901", "TH902" and "IC8841" to prevent the internal tempera-
ture rising abnormally and to control the cooling fans. (refer to "Fan control circuit" for detail)
If the internal temperature rising abnormally over the threshold value, the IC301 shuts down after cooling.
Service port
The mini DIN-8 pin jack is used for service the projector with RS-232C. The RS-232C Rx/Tx signals are connected
to pins 202 and 265 of IC301 via IC3801(RS-232C RECEIVER/DRIVER). The main program and data are stored
in IC801(FLASH ROM). The program can be replaced with new one by specified software "FlashUpgrader".
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Chassis Block Diagrams