Sanyo PLC-SU70 Service Manual

Also see for PLC-SU70: Owner's manual

Sanyo PLC-SU70 Service Manual Manual pdf 43 page image

-43-No PowerReset switchThe microprocessor inside the projector may occasionallymalfunction and does not accept any controls. In this case,press the reset switch on the rear panel with a sharp toolto restart the projector.- When all of LED indicators are not lighting, the symptom indicates that the primary power supply circuitdoes not operate properly. Check the power primary circuit and parts as follow;AC cordF601 (Fuse)Power boardSW902 (Thermal sw.).......short in normalSW902 opens when the surrounding temperature of the switch exceeds 105°C.This projector provides a function which can be specified a defective area simply by indicating the LEDs. Connectthe AC cord and press the Power button once and then check the LED indication.- When the WARNING (red) and POWER(red) indicators are flashing, the symptom indicates that the pro-jector detected an abnormal temperature risen inside the projector. Check the air filters and remove the objectnear the intake and exhaust fan openings, and wait until the POWER indicator stops flashing, and then try toturn on the projector.The internal temperature is monitored by sensor ICs, IC8801, IC8821 and IC8831 on the Main board.- When the WARNING indicator lights red, the symptom indicates that the projector detected an abnormalityin the cooling fan operation or in the power supply secondary circuits. Check fan operation and power supplylines, and the driving signal status.The POWER_FAIL signal (Error: L) is sent to pin 152 of IC301 when the abnormality occurredinside the projector, and then the IC301 sends the shut down signals, DC_ON and LAMPDC_ON, to the power supply cir-cuit to stop its operation, and signal BALAST_AC to the lamp ballast board via IC4891 and SW901 tostop operation of the lamp circuit.An abnormality occurs on the secondary power supply;Check power supplies 15.5V, S15.5V, S6V, S-5V. P_FAIL signal becomes “Low” when the abnormality occurs on any ofthe power supply lines.An abnormality occurs on the fan control circuit;Check FN901, FN902, FN903, FN904, FN905, FN906 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 becomesLow and is sent to lamp ballast board to stop lamp circuit.An abnormality occurs on the drive signals;DC_ON signal (Power-on: H) is output from pin 72 of IC301 and supplied to power supply circuit.LAMPDC_ON signal (Power-on: H) is output from pin 73 of IC301 and supplied to the P.F Control IC, IC621, on thepower supply board through Q651, and PC643.BLAST_AC signal (Power-on: H) is output from pin 81 of IC301 and applied to pin 2 of IC4891 and output pin 4 and thensupplied to the lamp ballast board through the Lamp Cover switch(SW901).CHO_RXD signal at the pin 140 of IC301 is applied from the lamp ballast unit. If the abnormality occurred on the lampballast unit, CHO_RXD signal becomes “High” and then IC301 shuts down the power supply circuit.TroubleshootingLamp Cover switchMake sure that the lamp cover is mounted correctly. If notor the lamp cover removed, the lamp does not light on forthe safety. Check the lamp cover and lamp cover switch(SW901).