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■ Troubleshooting
No Power
This projector provides a function which can be specified a defective area simply by indicating the LEDs on the con-
trol panel. Connect the AC cord and press the Power button once and then check the LED indication.
- When all of LED indicators are not lighting, the symptom indicates that the primary power supply circuit
does not operate properly. Check the power primary circuit and parts as follow;
AC cord, Fuse, Power AC board, Power DC board
SW905 (Thermal switch.) short in normal
SW905 opens when the surrounding temperature of the switch exceeds 100°C.
- When the WARNING (red) and POWER(red) indicators are flashing, the symptom indicates that the projec-
tor detected an abnormal temperature risen inside the projector. Check the air filters and remove the object
near the intake and exhaust fan openings, and wait until the POWER indicator stops flashing, and then try to
turn on the projector.
The internal temperature is monitored by sensor ICs, IC8801 and IC8811 on the Main board and IC2831 on the
Temp Sensor board.
- When the WARNING indicator lights red, the symptom indicates that the projector detected an abnormality
in the cooling fan operation or in the power supply secondary circuits. Check fan operation and power supply
lines, and the driving signal status.
The P-FAIL signal (Error: L) is sent to pin 184 of IC801<SUB CPU> when the abnormality occurred inside the projector,
and then the IC801 sends the shut down signals, IC_RESET and LAMP_SW, to the power supply circuit and lamp ballast
circuit to stop the operation.
The P-FAIL signal is separated to P-FAIL-L, P-FAIL-H and P-FAIL-P and these are detecting the power error in the circuits
listed below;
An abnormality occurs on the secondary power supply (P-FAIL-L);
Check power supplies 7V, 5V. P-FAIL-L signal becomes "Low" when the abnormality occurs on any of these power sup-
ply lines.
An abnormality occurs on the secondary power supply (P-FAIL-H);
Check power supplies 15.5V, 12V, 15.5VMT. P-FAIL-H signal becomes "Low" when the abnormality occurs on any of
these power supply lines.
An abnormality occurs on the power supply (P-FAIL-P);
Check the Power DC board. P-FAIL-P signal becomes "Low" when the abnormality occurs in the Power DC board.
The FAN_LOCK signal (Error: High) is sent to Q4801 when one of the fans stops operating. The FAN_LOCK signal is
applied to pin 19 of IC1811 <I/O Expander> by the name of FAN_DET signal and then IC801 detects an abnormality.
Check fans FN901, FN902, FN903, FN904, FN906, FN907 and FN908 and peripheral circuit.
The LAMP_SW signal (Power-on:H) is output from pin 206 of IC801 and applied to pin 2 of IC4801. The P-FAIL signal is
applied to pin 1 of IC4801. The IC4801 outputs the LAMP_SW signal to the lamp ballast unit through the Lamp Cover
switch(SW902).
LAMP_RXD signal at the pin 3 and LAMP TXD signal at pin 1 of IC801 are used for communication with the lamp ballast
unit through the IC4806. If the abnormality occurred on the lamp ballast unit, IC801 detects the abnormality by these sig-
nals and shuts off the lamp driving circuit.
Lamp Cover switch
Make sure that the lamp cover is mounted correctly. If not or
the lamp cover removed, the lamp does not light on for the
safety. Check the lamp cover and lamp cover switch
(SW902).
Reset switch
The microprocessor inside the projector may occasionally
malfunction and does not accept any controls. In this case,
press the reset switch on the rear panel with a sharp tool to
restart the projector.
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