No Power - Sanyo PLC-XE50 Service Manual

Sanyo plc-xe50 multimedia projector service manual
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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  a ll 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.)
-   W hen 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.
The internal temperature is monitored by sensor ICs, IC8811(Lamp), IC8821 (Panel) on the Main board and
IC4831 (Room) on the Temp. board
-     W hen 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 215 of IC301<SCALER> when the abnormality occurres inside the
projector, and then the IC301 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;
Check power supplies 16V, S6V, S-5V S16V. 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, 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_15.5V signal (Power-on: H) is output from pin 344 of IC301 and 16V supply circuit. ON_5VA signal
(Power-on: H) is output from pin 110 of IC301 and switches Q3582, 5VA supply circuit. 9V_AUDIO supply
circuit. ON_3.3V signal (Power-on: H) is output from pin 345 of IC301 and switches IC1401, 3.3V_A supply
circuit and IC7261.
LAMPDC_ON signal (Power-on: H) is output from pin 89 of IC301 and supplied to the P.F Control IC,
IC601, on the power supply board through Q681, and PC602.
BALAST_AC signal (Power-on: H) is output from pin 413 of IC301 and applied to pin 2 of IC4891 and out-
put pin 4 and then supplied to the lamp ballast board through SW901<Lamp Cover SW>.
CHO_RXD signal at pin 26 of IC301 is applied from the lamp ballast unit. If the abnormality occurred on
the lamp ballast unit, LAMP_DET/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).
short in normal
SW902 opens when the surrounding temperature of the switch exceeds 100°C.
- 73 -
Troubleshooting

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