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1 LCD driver board, introduced the principle

LCD screen driver board is often referred to as A/D (analog / digital) board, which in a sense reflects the main functions of the driver board to achieve. LCD screen to display images need to be digitized video signal, LCD driver board is completed from the analog signal to digital signal (or from a digital signal to another digital signal conversion module, and at the same time in the image control unit control continue to drive the LCD screen display image. The driving plate of the liquid crystal display is shown in Figure 1 and figure 2.

Figure 1 the driving plate used in the brand LCD display

Figure 2 Part of the liquid crystal display using a common driver board

The LCD driver board usually consists of main control chip and MCU micro controller, ROM memory, power supply module, a power supply interface, a VGA video signal input interface, OSD button interface board, high-pressure plate interface, LVDS/TTL drive screen signal interface and so on.

LCD driver board schematic diagram as shown in Figure 4, from the host computer display cards sent the video signal, through the drive plate on VGA video signal input interface into driver in the main control chip, main control chip based on MCU micro controller in the LCD screen control LCD screen image is presented. At the same time, MCU microcontroller to achieve the power control of the whole machine, functional operation, etc.. Therefore, the liquid crystal screen driver board is also called the main board of the liquid crystal display.
LCD driver board is damaged, may cause can not boot, the boot black screen, screen, screen flowers, ripple interference, keypad failure etc. fault phenomenon, in the liquid crystal display fault occupies a larger proportion. Large scale integrated circuit and chip components are widely used in the LCD driver board, and the layout of the circuit elements is tight.

Gather together, to find the specific components or running the line has caused great difficulties. In non factory conditions, the repairable less, if the drive plate due to the part of the power supply, VGA video input interface circuit part of the damage caused by the fault, as long as there is a circuit of knowledge we can easily solve, for those due to MCU micro controller internal data damage caused can not work normally drive plate, in the premise of data files (driver), we can with liquid crystal display programmer of the MCU microcontroller data programming, to repair the firmware damage caused by the fault. Early driver board, the need to remove the MCU microcontroller to operate, there is a certain difficulty. Currently the driver board has generally started to support ISP (online programming) MCU microcontroller, so that we can through the ISP tool online MCU microcontroller internal data to burn and write. We use the latest EP1112 LCD programmer can complete such as this work .

In the maintenance of liquid crystal display, when the malfunction of the driving plate, if liquid crystal display originally used is general drive plate, can directly find corresponding motherboard substitution treatment, of course, still need in the MCU write with corresponding to the LCD screen driver. If the driver board is brand machine motherboard, we generally use the common market "universal driver board" substitution method for maintenance;

Universal drive board, also known as universal drive board". At present, the common market "generic driver board" Leroy, Ding branch, triumph, yuekang etc. brand, as shown in Figure 5, although this kind of "general driver board" the components and the original driver board "inconsistent, but as long as the liquid crystal display programmer" universal driver board "to write corresponding to the LCD screen driver (the purchase of programmer will randomly send LCD screen driver CD), by simply connecting line, it can drive a different liquid crystal display screen, strong versatility, and the maintenance cost is is not high, users can easily accept.

Leroy 68167/NA91B general drive plate

Leroy RM3331B general drive plate

Leroy MA4B general drive plate

Topscien 2013B general drive board

Because the LCD screen a variety of signal interface and general drive plate and the liquid crystal screen signal line (TTL/LVDS signal line) also has a variety of, the following is specific models: use the generic driver board "substitution of LCD driver board screen and change the line, the installation of three links.

2, point screen tools and point screen skills

Screen is the original LCD liquid crystal screen out (no need for all other parts of the original liquid crystal display), again according to the types of LCD screen, with a programmer to general driver board written with a corresponding to the LCD driver, using this general drive plate in combination with other screen accessories (high pressure, key board, screen line), lit LCD screen, can display images, without and corresponding to the LCD driver, need to find compatible driver, with a programmer to general drive plate will continue to write procedures, until the light screen. This can drive the LCD driver board general can be used for replacing the original LCD damaged the main control board.

The LCD driver board principle and maintenance replacement method

1 LCD driver board, introduced the principle

2, point screen tools and point screen skills