No Power - Sanyo PLC-XE32 Service Manual

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,
SW90 (Thermal sw.)
- When the WArNING (red) and PoWer(red) indicators are flashing, the symptom indicates that the projector de-
tected 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, IC881 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 P_FAIL signal (Error: L) is sent to pin 15 of IC301<SYSTEM CONTROL> when the abnormality occurred inside the
projector, and then the IC301 sends the shutdown signal, LAMP_DC_ON, to the power supply circuit to stop its opera-
tion, and signal BLAST_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, 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, FN90, FN903, FN904 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;
ON_150V signal (Power-on: H) is output from pin 01 of IC301 and switches IC5701,15.5V supply circuit, ON_50V
signal (Power-on: H) is outut from pin 110 of IC301 and switches Q358, 5VA supply circuit, ON_33V signal (Power-
on: H) is output from pin 11 of IC301 and switches IC5631, 3.3V supply circuit and IC491, 1.8V supply circuit.
LAMP_DC_ON signal (Power-on: H) is output from pin 363 of IC301 and supplied to the P.F Control IC, IC61, on
the power supply board through SW90<Thermal SW>, Q651, and PC643.
BLAST_AC signal (Power-on: H) is output from pin 111 of IC301 and applied to pin  of IC4891 and output pin 4
and then supplied to the lamp ballast board through SW901<Lamp Cover SW> on the MSW board.
LAMP_DET signal at the pin 90 of IC301 is applied from the lamp ballast unit. If the abnormality occurred on the
lamp ballast unit, LAMP_DET 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).
short in normal
SW90 opens when the surrounding temperature of the switch exceeds 105°C.
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