After investigation, the AC fuse intact, but P82 feet without output 5V, P83 6 feet without 142V (+ b) output, 1 foot 2 feet nor 15V and 16V output. There is no short circuit phenomenon in the power supply of the power supply, which is a part of the switch power supply. Carefully check the switch power supply, found that the IC802 has been blown open a thin gap, D824, R807, Q804, R814, R826 have been damaged. In addition, but also check IC803 and D803. Otherwise, after the change of the power supply voltage of two times higher than the loss caused by. The D803 has also been damaged. Finally, check the Q807. IC802 model for S6708 STR, is a new type of power supply thick film integrated block, the market has two kinds of sales. One is the three row of pins, and the printed circuit board hole one one corresponding, easy to install, easy to weld, but the price is very expensive. Another is the two rows of pins, before installation to the plastic into three rows of pins with pointed nose pliers, a row of pins just to avoid strong through the printed circuit board hole flat, welding must pay attention do not weld, but the price is very cheap. The two can be used, do not have to worry about. Type of Q804 2SC1984ZF and its parameters for: BVcbo=100V, Icm=3A, PCM=30W, Hfe=50 ~ 2000, measured generally at around 700, is Darlington tube, such as Tesco, also available in other types of pipes, such as 2SD1277A, 2SD1276A or 2SD1275A substitution is also very good, and the price is cheap. D824 model for H - MA4062, is the 6.2V regulator diode, no special requirements, but we must pay attention to the selection of the value of the 6V above, the regulator is low, the switch power will not play. D803 model for the TLP621GR-LF2, is a photoelectric coupler, all the components are welded, the general power to work normally. But this time it is not, after the boot of the indicator light that is out, after the measurement + B voltage on a liter up and down immediately. Carefully examined, and alcohol cleaning printed circuit board after the discovery, D631 have end weld is very subtle, post welding troubleshooting, the boot that is the grating appears. But did not think this is a strange phenomenon occurs, a power that is AV state, and the volume automatically rose to the maximum. And, whether analog selection any are automatically rise to maximum. Even according to the remote control device to cut down, but let go of the release button is automatically increased to the maximum and remote control function disorder. Why have these strange phenomenon?? after the microprocessor detects and jade like stone feet, the foot of the Liu, Yao feet were 0V, normal respectively 4.8V, 4.8V and 3.6V, jade like stone feet Liu feet were for 0V, P82 feet 5V did not add to the motherboard. After investigation, it was found that P82 bad contact, managed to all good contact and remote control all the functions were restored to normal, fault completely ruled out. Because this large screen color TV in the maintenance of the power supply part is to take it under separate repair, when the P82, P83 two press type lap line has set off a side, and the main board. After the completion of the test with the main board, P82, P83 is very easy to overlap, please pay close attention to the restoration. Also, in the maintenance of this power should be in the P82 II Q806 between the base and the ground temporarily to a 3K or so resistance, otherwise the switch power will not work. After the repair, do not forget to take this resistance.