Epson PowerLite 5000, Service Manual

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EPSON PowerLite 5000 Service Manual
2-32
The power supply unit cable is connected with a fastening tab to the safety switch. When
the temperature rises to a certain temperature, all regulating operations of the power
supply unit are stopped and power is shut off. Once this switch runs, you cannot start the
power until the temperature falls to a certain temperature. In this case, you must also
consider the lamp thermistor or the main board may be defective.
2.13.4 Lamp Thermistor
This is the temperature detection thermistor installed on the lamp outer housing (near the
safety switch). To protect the light source lamp from overheating, this thermistor shuts off
the power on the power supply unit if the temperature rises to a certain temperature (lower
than the safety switch
’ s level).
Lamp Thermistor
Figure 2-31
The lamp thermistor is connected to CN804 on the main board. If there is overheating,
IC600 generates an interrupt signal and shuts off power on the power supply unit via
CN800.
2.13.5 LV Thermistor
This is the temperature detection thermistor installed on top of the light valve. If cooling is
not sufficient because of intake fan failure (installed at the bottom of the light valve) or filter
contamination (installed at the top of the light valve), the power is shut off to protect the
light valves from overheating. The light valve (liquid crystal panel) has poor thermal
stability. The power shut off control is the same as the lamp thermistor
’ s, described in
section 2.13.4.