1. Separate T-CON board circuit
3. High-voltage board, T-CON board and side board are integrated
The faults in the side strips are mainly manifested as: black screen, gray screen, blurred screen, vertical lines on the screen, vertical strips, etc.The main cause of the above-mentioned faults is caused by water in the side strips!
A. Causes of water ingress in the edge strips: Traditional CRT TVs are made of the entire glass cone with no connectors around. The current LCD screens use TAB elements, components, and COF to connect with the PCB board.The user still wipes the screen with a wet cloth like CRT, it is easy to get water in, especially when the LG screen side board is inverted , The sidebar is below, the failure rate is particularly high. As long as the water enters the side board, it will corrode and seriously burn out the COF and OC. Because the user’s home is too tightly sealed and poorly ventilated in winter, it is easy to produce water vapor under the action of heating, which flows to the side along the screen On the board. In summer, under the drive of air conditioning, it is easy to cause water in the edge strips. Especially in the south, it is wet and humid, and the failure rate of the edge strips is higher. Household cleaning is also an important link that causes water to enter the side strips. There are also reasons such as children playing with water guns and installing TVs under the air conditioner, etc., which may cause water to enter the screen.
The maintenance idea of the side board part analyzes the gray screen, black screen or abnormal screen light-emitting maintenance methods: when the LCD screen has the edge strips, the main manifestations are the following situations: 1. The TV can be watched normally, but occasionally the grating side is bad. The phenomenon can be normal in an instant, and it is generally difficult to find. 2. The left or right grating appears on the TV screen. .3. The backlight is bright and the screen is not bright. Maintenance method: For the fault that the backlight is bright and the screen is not bright, you should first measure whether the logic board LVDS power supply 12 volts is normal. There are two situations at this time: (1) Normal. (2) The fuse has blown. If 12 volts is normal, you should measure the relevant voltages such as VCOMVGH, VGL, and focus on measuring the output voltage VG1-VG21. If it is still abnormal, the logic board is damaged. If it is normal, there is no doubt that water has entered the side board. For the open circuit fault of the fuse on the logic board, it is not allowed to replace the fuse or directly short-circuit with a wire. The resistance value of the two ends of the fuse to the ground should be measured. If there is a short-circuit to ground, please check the cause. If the resistance to ground is large, it means that there is no short-circuit problem. You should disconnect the flexible cable between the logic board and the edge strip and replace the fuse. If it is normal at 12 volts, it means the LCD screen Water in. At this time, you can connect the two flexible cables from the logic board to the side board only one way to determine the position of the water inlet.