TCL LCD TV L40E9SHBD MS68 movement blue light is not turned on, the machine blue light is on, the voltage of each voltage regulator block is measured, the reset voltage of the main chip is abnormal, and it fluctuates around 2V. The machine should be a high level reset, and the reset port is reset. The voltage should be zero V. Temporarily remove the reset circuit and reset it manually. The so-called manual reset is to contact 5V at the reset port of the main chip. After manual reset, the fault remains. . 3.2V105Ah Lithium Ion Battery,105Ah 3.2V Phosphate Battery Cell,3.2V105Ah Deep Cycle Solar Battery,3.2V 105Ah Lifepo4 Forklift Battery Jiangsu Zhitai New Energy Technology Co.,Ltd , https://www.zhitainewenergy.com
Remove the reset circuit, the reset port voltage of the main chip is zero, but the measured voltage fluctuates around 2V at this time. Obviously, there is a problem with the reset port of the main chip, and the main chip is judged to be damaged. . . .
Suddenly, can you add a so-called bleeder voltage resistor to the main chip? Then the 750 ohm resistor is used to connect the reset port of the main chip to the ground. At this time, the fluctuation 2V voltage is measured to disappear.
After manual reset, it is found that the backlight is on at this time, obviously the fault is eliminated, the original reset circuit is restored, and the fault is eliminated. . .