No Power - Sanyo PLC-WXU700 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.
- W hen 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.) short in normal
- When the WArNING (red) and POWer(red) indicators are flashing, the symptom indicates that the projector
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.
T he internal temperature is monitored by sensor ICs, IC6611(Lamp), IC661 (Panel) on the Main board and
IC481 (Room) on the Temp. 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.
T he P_FAIL signal (Error: L) is sent to pin 81 of IC01<SCALER> when the abnormality occurs inside the
projector, and then the IC01 sends the shutdown signal, LAMPDC_ON, to the power supply circuit 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;
C heck 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, FN90, FN904, FN905, FN907 and peripheral circuit.
I f any of the fans has an error, the fan lock signal drives Q780 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;
O N_15V signal (Power-on: H) is output from pin 5 of IC01 and IC59,15.5V supply circuit. ON_5V signal
(Power-on: H) is output from pin 148 of IC01 and IC5461, 1V supply circuit and switches IC5081, 5V_AU-
DIO supply circuit. ON_.V signal (Power-on: H) is output from pin 5 of IC01 and switches Q58,
.V supply circuit and IC561, 1.0V supply circuit.
L AMPDC_ON signal (Power-on: H) is output from pin 0 of IC01 and supplied to the P .F Control IC, IC601,
on the power supply board through Q681, and PC60.
B ALAST_AC signal (Power-on: H) is output from pin 7 of IC01 and applied to pin  of IC4891 and output
pin 4 and then supplied to the lamp ballast board through SW901<Lamp Cover SW>.
R XD1 signal at pin 445 of IC01 is applied from the lamp ballast unit. If the abnormality occurred on the
lamp ballast unit, RXD1 signal becomes "High" and then IC01 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).
S W90 opens when the surrounding temperature of the switch exceeds 100°C.
Lamp cover switch
(SW901)
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