No Power - Sanyo PLC-XU106 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
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, IC8831(Lamp), IC881 (Panel) on the Main board and
IC4831 (Out side) 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.
The P_FAIL signal (Error: L) is sent to pin 15 of IC301<SCALER> when the abnormality occurs inside the
projector, and then the IC301 sends the shutdown signal, LAMP_DC_ON, to the power supply circuit 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;
Check power supplies 15V, S6V, 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, FN905, FN907 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 40 of IC301,15V supply circuit.
ON_50V signal (Power-on: H) is output from pin 97 of IC301, 5VA supply circuit and switches IC5061,
5V_AUDIO supply circuit. ON_33V signal (Power-on: H) is output from pin 188 of IC301 and switches
Q358, 3.3V supply circuit.
LAMP_DC_ON signal (Power-on: H) is output from pin 89 of IC301 and supplied to the P.F Control IC,
IC631, on the power supply board through PC661.
Lamp_SCI signal (Power-on: H) is output from pin 14 of IC9885 and applied to pin  of IC4891 and output
pin 4 and then supplied to the lamp ballast board through SW901<Lamp Cover SW>.
CHO_RXD signal at pin 16 of IC9885 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
SW90 opens when the surrounding temperature of the switch exceeds 100°C.
-58-
SW901