Canon LV-7215U Service Manual

Contents

Canon LV-7215U Service Manual Manual pdf 67 page image

Part 4: Troubleshooting4-11. TROUBLESHOOTING1.1 No PowerThis projector provides a function which can be specified a defective area simply byindicating the LEDs on the control panel. Connect the AC cord and press the Powerbutton once and then check the LED indication. When all of LED indicators are not lighting, the symptom indicates that the primarypower supply circuit does not operate properly. Check the power primary circuitand parts as follow;• AC cord• F601 (Fuse)• Power board• SW902 (Thermal sw.) .............................short in normalSW902 opens when the surrounding temperature of the switch exceeds 90°C. When the WARNING (red) and POWER (red) indicators are flashing, the symptomindicates that the projector detected an abnormal temperature risen inside theprojector. Check the air filters and remove the object near the intake and exhaustfan openings, and wait until the POWER indicator stops flashing, and then try toturn on the projector.The internal temperature is monitored by sensor ICs, IC2801, IC2831 andIC2861 on the Main board. When the WARNING indicator lights red, the symptom indicates that the projectordetected an abnormality in the cooling fan operation or in the power supplysecondary circuits. Check fan operation and power supply lines, and the drivingsignal status.The P_FAIL signal (Error: L) is sent to pin 48 of IC801_{when the}abnormality occurred inside the projector, and then the IC801 sends the shut downsignals, 5V_SW and LAMP_BST_SW, to the power supply circuit to stop theoperation.• 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 of the power supply lines.• An abnormality occurs on the fan control circuit;Check FN901, FN902, FN903, FN904, FN905, FN906 and peripheral circuit.Check Q67P, D67P, Q68P, D68P and peripheral circuit (Over voltagedetection circuit).