Sanyo PLC-EF31 Service Manual

Also see for PLC-EF31: Owner's manual Service manual

-5-❏ Overheat Protection -- The temperature monitor system --"SW904" Temperatureswitch for Lamp-1.It operates at 80˚C"SW903" Temperatureswitch for Lamp-2.It operates at 100˚CPRESSURESensorIC886TemperatureSensorIC2541TemperatureSensorIC5801B-SideMain boardA-Side"SW904" Temperatureswitch for Lamp-1.It operates at 90˚C"SW903" Temperatureswitch for Lamp-2.It operates at 100˚CPRESSURESensorIC886TemperatureSensorIC2541TemperatureSensorIC5801Temperature sensorslocation----- 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 sensor-IC5801 and it checks anatmospheric pressure using pressure sensor-IC886.CPU judges data from sensors and controls the air flow of the cooling fans sothe temperature inside the projector is maintained to normal temperature. To shut down the projector urgent.The CPU checks temperature of Red-LCD panel periphery (IC2541) andinhalation air(IC5801). If each part temperature reaches to abnormal temper-ature(IC2541 ; 47degrees / IC5801 ; 42degrees),the CPU will turn off a projector, and will blink TEMPERATURE WARN-ING indicator at intervals of 0.6 seconds. Cooling fans operate until tempera-ture returns to normal. Indicator will stop blink, if temperature returns to nor-mal. Trace the cause of an unusual temperature, and repair the projector.(Refer to the item of " temperature abnormality" of troubleshooting.)D7/E7The temperature monitor system is provided to prevents damage of optical components (the LCD panel and polarization film etc.)inside a projector from overheat. Two protection systems are provided.Each system operation as follows ;----- The temperature monitor -2 : ----- Temperature check of lamps.Temperature switches (SW 903~904) are arranged near the two lamps.Temperature switches will operate, if temperature reaches 90~100 degrees.SW904 (Lamp-1)----- It operates at 90 degrees.SW903 (Lamp-2)----- It operates at 100 degrees.When temperature switches have operated, lamp ballast units will be shutdown, then a projector will be turned off. Note;(1) If other protection equipments ( The function of fan operation check, The func-tion of voltage check "Power-failure" and Temperature monitor 1 ) are rightlyoperating, the lamp does not become an unusual temperature. So, the temperaturemonitor 2 rarely operates. However, when those protection equipments do notoperate with fault, the temperature monitor 2 operates and the broken protectionequipment is covered. If this temperature monitor 2 operates, it is thought fault ofother protection equipments. Also trace the cause of fault of other protectionequipments with the cause of an unusual temperature.(Refer to the item of " temperature abnormality" of troubleshooting.)(2) The CPU does not check operation of temperature switches. Therefore, whentemperature switches have operated and a projector has shut down, TEMPERA-TURE-WARNING indicator does not blink.D7/E7