No Power - Sanyo PLC-WL2500 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,
SW902 (Thermal sw.) . .............. short in normal
S W902 opens when the surrounding temperature of the switch exceeds 85°C.
- W hen the WArNING (red) and POWer (red) indicators are blinking, 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 blinking, and then try to turn on the
projector.
T he internal temperature is monitored by sensor ICs, IC8821 on the Main board and IC8811 on the Temp Sen-
sor A board, IC8831 on the Temp Sensor C 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 215 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 cir-
cuit to stop its operation, and signal LAMP_SCI 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 S16V, 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, FN907 and peripheral circuit.
I f any of the fans has an error, the fan lock signal drives Q3601 becomes "High". 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_150V signal (Power-on: H) is output from pin 95 of IC301 and switches IC592,15.5VPNL supply circuit.
O N_33V signal (Power-on: H) is output from pin 188 of IC301 and switches IC5621, 1.0V and Q3582 3.3V sup-
ply circuit. ON_50V signal (Power-on:H) is output from pin 419 of IC301 and switches IC5542, 12V supply circuit.
ON_16V signal (Power-on:H) is output from pin 96 of IC301 and switches Q5701, S-5V supply circuit.
L AMP_DC_ON signal (Power-on: H) is output from pin 89 of IC301 and supplied to the P.F Control IC, IC621,
on the power supply board through PC661.
L AMP_SCI signal (Power-on: H) is output from pin 14 of IC9885 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>.
L AMP_DET signal at the pin 285 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).
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