Question

What is LCD screen failure, what is logic board failure

Answer 1

LCD screen failure and logic board failure are two common types of failures in LCD TVs, which involve different components and failure manifestations.

LCD screen failure

The LCD screen is the core display component of the LCD TV, responsible for converting electrical signals into visible images. LCD screen failure usually manifests itself in the following situations:

1. Black screen: The LCD screen does not display any image at all, but may be accompanied by sound or the backlight is working normally. This may be caused by LCD damage, driver board problems, or signal transmission problems.

2. White screen: The LCD screen displays a full white screen and cannot present a normal image. This is usually caused by the LCD screen not receiving the signal correctly or the driver board failure.

3. Flower screen: Color blocks, stripes, or image distortion appear on the LCD screen, affecting normal viewing. This may be due to problems with the LCD screen itself, such as pixel damage or abnormal signal transmission.

4. Gray screen: The LCD screen displays a gray screen, lacking color and details. This may be due to problems with the LCD screen backlight but problems with signal transmission or processing.

Solutions to LCD screen failures usually include replacing the LCD screen, repairing the driver board, or checking the signal transmission line.

Logic board failure

The logic board is an important component in LCD TVs, responsible for receiving and processing video signals from the signal source and converting them into a format that the LCD screen can recognize. Logic board failure usually manifests itself in the following situations:

1. No image: The TV screen has no image display, but there may be sound or the backlight is working properly. This may be caused by no power supply voltage to the logic board, a blown fuse, or a signal transmission problem.

2. Abnormal image: The TV screen displays an image but the color, contrast, or clarity is abnormal. This may be caused by a circuit failure on the logic board, a damaged integrated block, or a signal processing problem.

3. Vertical bands or other image problems: Vertical bars, noise points, or unclear image levels appear on the screen. This may be due to a connection problem between the logic board and the LCD screen or a failure of the logic board itself.

Solutions to logic board failures usually include checking the power supply voltage, replacing the fuse, repairing the circuit, or replacing the logic board.

In general, LCD screen failures mainly involve problems with display components, while logic board failures involve problems with signal processing and transmission. In the actual repair process, it is necessary to determine whether it is an LCD screen failure or a logic board failure based on the specific fault phenomenon and test results, and take corresponding solutions.

Answer 2

LCD screen failure analysis can be summarized as follows:

1. Display abnormality: such as black screen, white spots, black spots, flowery screen, etc., may be caused by damage to the backlight panel, damage to the liquid crystal molecules, driver board or image processing chip failure.

2. Color problem: uneven color and distortion may be caused by improper color settings, display control board failure or color filter problems.

3. Physical damage: such as scratches and cracks, usually caused by external impact or improper use, the screen needs to be replaced or protective measures taken.

4. Connection problem: The screen cable is loose or damaged, which will affect the signal transmission and cause abnormal display. The screen cable needs to be reconnected or replaced.

In summary, LCD screen failures are diverse, and the causes need to be analyzed according to the specific symptoms and corresponding measures need to be taken to solve them.