Driving pulses to start its operation , the projection lamp to provide a suitable working voltage , into the normal lighting state .

 

    The projector according to the principle of the ballast circuit of the timing , the performance of a fault with the present embodiment , when starting very low measured Q706 b (OV), c is extremely high (13.2v), the timer proof The control circuit is normal. And then measuring the voltage approximates Q707 b 0V, while C711 positive voltage only 3.5V, and no significant increase in performance. Suspicious element analysis leads to this abnormal phenomenon is only the resistance value of R723 larger, open or C711 leakage , tested C711 serious leakage . Since C71l serious leakage , ZD701 (6.8V) deadline , Q707 is also off , so that the coil of the relay RY702 no current can not pull through , leading to failure in this case . After replacing C71l, troubleshooting. Voltage shown in the drawings is projected value after the end of the normal operating voltage to start the lamp .

 

    Note: Due to the ballast assembly is an important component of LCD projectors , reliability is critical of their work ; coupled with large power consumption of the component , so the replacement of other components must be careful with the application of the principles original replacement device the same size , forced substitution when needed , they should ensure that the main parameters of the original equal or win, for the secondary parameters can be relaxed , or they may reduce the reliability and security. Combined in this example C71l, the circuit requires the installation of its parameters and environmental factors considered , you must use low leakage, high stability, high temperature resistant varieties, or they may reduce the reliability of their work or cause it to early failure.

 

    In addition , in the use and maintenance of the LCD projector , encountered the phenomenon of projection lamp does not light , do not ignore the fans and the import and export projection lamp cover safety switch , etc. (XV a 100ZM projector no such safety switch Father ) , should observe panel lights on the machine tips . All have LCD projector projection lamp failure and ultra-high internal temperature warning light signals , which the machine is too high temperature warning light for some time after the appearance of the machine work , but also accompanied by the projection lamp shuts down, for such failure overhaul under the wind into the wind and a good premise of the system ; while the projection lamp failure warning light is not successful after the first start , the control system of the host microprocessor test them several times to start after the failure still occurs , specific test start times vary slightly depending on the model , the majority of between 3 to 5 times (XV-1OOZN projector is 5 times ) .

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