Use the frequency file to repair the LCD TV does not boot 1 case - android - Phones Developers

Filter 18.432M

Renovated an ENVISION brand 22-inch LCD TV produced by Fujian Jielian Electronics Co., Ltd. The fault phenomenon is that the red indicator light is on after power-on. After the standby button is pressed twice, the red indicator light is off, the green indicator light flashes and then goes out, the red indicator light is on again, and the TV returns to the standby state. According to the fault phenomenon, it seems that the power supply can not afford the load! Use a multimeter to test the 5V and 12V output voltages of the IP board are normal. Is it 5V or 12V voltage ripple? ! Use the multimeter frequency file to test the 5V output without frequency, but the 5V π-filter front end is found to have a frequency! Replace the filter capacitor 16V/330UF of the π-type filter front end and test the machine OK. However, when the faulty capacitor is replaced, the pointer swing is normal when tested with the pointer meter, and the digital meter capacitance test shows 321.6 UF.

TV model

Frequency value measured at fault

Replace faulty component

Normally measured frequency value

The picture after the TV is working normally.