Service manual

2-18
EMP-S3
SEIKO EPSON Revision:B
Thermistor and Temperature Sensor Operation
Analog/Digital converters in IC702 and IC703 (V850) on the MA board detect the tempera-
tures of the Optical Engine and Power Supply sections by means of the two Lamp Thermistors
at intervals of 1 second. Based on the measurement results, the CPU controls fan operations
and power supply shutdown operations as necessary.
See Section 2.8.2 for more information on fan operation, and Section 2.9 for more information
on the LED status indicators.
2.8.2 Fan Operation
There are four cooling fans inside the projector. These fans discharge heated air produced by
the Lamp Assy., power supply unit, and ballast unit.
Figure 2-22. Fan Locations
Table 2-4. Temperature Sensors
Condition Warning Indicator Meaning
Normal temperature Off Normal operation in progress
Warning temperature Flashes orange
If temperature rises any higher, projection
stops.
Abnormal temperature Steady red Overheating (no projection)
Internal error Flashes red
Problem with fans, thermistors or temper-
ature detection circuit
Exhaust FanPower Supply Fan
Intake fan 1 Intake fan 2