Introduction To The Principle Of LCD Driver Board
January 4, 2022
The LCD driver board is often called A/D (analog/digital) board, which in a sense reflects the main functions of the driver board. To display images on the LCD screen, a digitized video signal is required. The LCD driver board is a functional module that completes the conversion from analog signal to digital signal (or from one digital signal to another digital signal), and at the same time in the image control unit The control goes down to drive the LCD screen to display images.
The LCD driver board usually contains the main control chip, MCU microcontroller, ROM memory, power module, power interface, VGA video signal input interface, OSD key board interface, high voltage board interface, LVDS/TTL drive screen signal interface and other parts.
The principle of the LCD screen driver board The video signal sent from the display card of the computer host is sent to the main control chip of the drive board through the VGA video signal input interface on the drive board. The main control chip is based on the information about the LCD screen in the MCU microcontroller. Control the LCD screen to present images. At the same time, the MCU microcontroller realizes the power control and functional operation of the whole machine. Therefore, the LCD driver board is also called the LCD motherboard.
If the LCD driver board is damaged, it may cause failures such as failure to boot, black screen, white screen, blurred screen, ripple interference, and button failure, which account for a large proportion of LCD failures.
Large-scale integrated circuits and chip devices are widely used in LCD driver boards, and the layout of circuit components is compact, which makes it difficult to find specific components or run lines. Under non-factory conditions, its repairability is relatively small. If the driver board fails due to damage to the power supply part and the VGA video input interface circuit part, as long as we have circuit knowledge, we can easily solve it. For those caused by the internal MCU microcontroller The data damage caused by the driver board cannot work normally. Under the premise of having the data file (driver), we can use the LCD programmer to program the MCU microcontroller to repair the malfunction caused by the firmware damage. In the early drive boards, it was necessary to disassemble the MCU microcontroller for operation, which was quite difficult. The current driver boards have generally begun to use MCU microcontrollers that support ISP (Online Programming), so that we can program the data inside the MCU microcontroller online through the ISP tool. For example, the dot screen driver version of 814-50-5 we use is the latest LCD monitor that can accomplish this kind of work.
In the maintenance of LCD monitors, when the driver board fails, if the LCD monitor originally uses a general-purpose driver board, you can directly find the corresponding motherboard to replace it. Of course, you still need to write in the MCU and the LCD screen. Corresponding driver; if the driver board is a brand-name motherboard, we generally use the common "universal driver board" on the market to replace it for maintenance;
"Universal driver board" is also called "universal driver board". At present, there are many brands of common "universal drive boards" on the market. Although the components used in this "universal drive boards" are inconsistent with the "original drive boards", as long as the LCD programmer is used to write the LCD to the "universal drive boards" The driver program corresponding to the screen (the LCD screen driver CD will be sent when you buy the programmer), and then you can drive different LCD screens by simply changing the wiring. It has strong versatility, and the maintenance cost is not high. It is easy for users accept.
Since the LCD screen has various signal interfaces, there are also various signal lines (TTL/LVDS signal lines) between the universal drive board and the LCD screen.
Use the "universal driver board" to replace the LCD driver board in three steps: screen, line change, and installation.