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Troubleshooting
No Power
This projector provides a function which can be specified a defective area simply by indicating the LEDs. 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
F601 (Fuse)
Power board
SW902 (Thermal sw.).......short in normal
SW902 opens when the surrounding temperature of the switch exceeds 105°C.
- When the WARNING (red) and POWER(red) indicators are flashing, the symptom indicates that the pro-
jector 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, IC8821 and IC8831 on the Main 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 POWER_FAIL signal (Error: L) is sent to pin 152 of IC301<SYSTEM CONTROL> when the abnormality occurred
inside the projector, and then the IC301 sends the shut down signals, DC_ON and LAMPDC_ON, to the power supply cir-
cuit to stop its operation, and signal BALAST_AC to the lamp ballast board via IC4891 and SW901<lamp cover switch> to
stop operation of the lamp circuit.
An abnormality occurs on the secondary power supply;
Check power supplies 15.5V, S15.5V, S6V, S-5V. P_FAIL signal becomes "Low" when the abnormality occurs on any of
the power supply lines.
An abnormality occurs on the fan control circuit;
Check FN901, FN902, FN903, FN904, FN905, FN906 and peripheral circuit.
If any of the fans has an error, the fan lock signal drives Q3601 becomes on. As the result, signal FAN_ERR becomes
Low and is sent to lamp ballast board to stop lamp circuit.
An abnormality occurs on the drive signals;
DC_ON signal (Power-on: H) is output from pin 72 of IC301 and supplied to power supply circuit.
LAMPDC_ON signal (Power-on: H) is output from pin 73 of IC301 and supplied to the P.F Control IC, IC621, on the
power supply board through Q651, and PC643.
BLAST_AC signal (Power-on: H) is output from pin 81 of IC301 and applied to pin 2 of IC4891 and output pin 4 and then
supplied to the lamp ballast board through the Lamp Cover switch(SW901).
CHO_RXD signal at the pin 140 of IC301 is applied from the lamp ballast unit. If the abnormality occurred on the lamp
ballast unit, CHO_RXD signal becomes "High" and then IC301 shuts down the power supply 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
(SW901).
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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