Filter 18.432M

In the middle and late last year, a middle-aged and elderly person was very polite to the store to consult, a TCL L46P10FBEG TV image in the home was dark. The brightness was not enough, but occasionally normal, good and bad, after-sales said possible screen problems, XX Ocean can repair. Can you show me it, but I can charge the door inspection fee.
Invisible visual inspection, the image is dark when the problem occurs, and the motion is tailed, the refresh is slow, as if the picture is fixed, the image is normal or not, the backlight is always normal, there is no protection, the meter output power output 5V.12V 24V is normal, output filtering The appearance of the capacitor is not pregnant, discoloration, the 5V 3.3V 1.8 of the motherboard and the 12V measurement of the logic board are no problem.
The target turns to logic several points of voltage value, DC-AC conversion point VGL=-7.VGH=26, VDD=16V drive IC power supply 3.3V, it seems that there is no problem. Strange? ? Obviously it is the problem of the gate turn-on voltage.
I took apart the screen and looked at the sideboard circuit. The new one is very non-corrosive. Only the welding table looks at the voltage and says it again. If the workmanship pays off, when the picture is tailed, a set of VGH voltage changes from 26v to -4.6v, haha, The problem is here, check the logic board to the screen cable jack is not 26v = -4.6v, but the DC-AC conversion has 26v, measured the resistance to the ground as if there is no leakage, it seems that between the lines There is a bad open contact, the line is too thin and too lazy to clean the line to save time.
Solution: Direct string 22K resistance flying line, test machine OK, has not called the feedback yet, there should be no problem.


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