There are sound, indicating that the normal audio amplifier 12V power supply, switching power supply work also shows normal. Measured with a spectrum analyzer crystal display panel (LCD) X pole (MOSFET source) input video signal is normal; but block dc voltage measurements with a multimeter LCD panel Y pole (MOSFET gate) voltage is 0V, the normal value should be about 5V driving pulse. The voltage of the switching power supply S2 winding rectified by D724, C733 filter, and then by IC702 (PQ05F11) provides regulated output 5V, IC2001 {58} pin 12V output voltage control IC702 via R761 +5 V output voltage on / off. Remove the D724 measure its positive and negative resistance value is normal; then remove the detector C733 normal; measured IC702 input voltage, but the output voltage is 0V. After replacing IC702, troubleshooting.6LWservice manual download site