Based on an analysis of common LCD screen failures, the primary issues can be categorized into problems with the backlight, internal components, pixels, and physical damage. The most frequent causes range from simple aging and loose connections to more severe electrical faults and physical trauma.
☆☆☆Backlight and power failures☆☆☆
These issues typically cause the screen to appear dark, dim, or flicker.
Backlight degradation: The LEDs or CCFL tubes that provide the screen’s light have a finite lifespan. As they age, they dim over time, eventually leading to full or partial failure.
Power supply and inverter problems: The inverter (in older CCFL-based displays) or the driver circuitry (for modern LED backlights) can fail due to aging capacitors, unstable voltage, or poor components. This can cause the screen to flicker or go completely black.
Loose or damaged cables: The signal cable that carries power to the backlight can become loose or damaged, particularly in laptops where it passes through the hinge. This results in intermittent flickering or a dim display.
☆☆☆Internal component and signal failures☆☆☆
These failures affect the screen’s ability to process and display an image correctly.
COF damage: LCD screen COF(Chip On Film), a key packaging technology for LCD modules. Its core is to fix the display driver IC(DDIC) chip on the flexible circuit board (FPC), electrically connect the Gold Bump of the chip with the Inner Lead of the FPC through hot pressing, and then fold the FPC to the bottom of the screen, instead of directly binding the chip on the glass substrate in the traditional COG(Chip On Glass) technology.Therefore, COF is an important part of LCD screen, which has a high calorific value and is easy to be damaged. Lines appear on the screen, or the display area connected with COF is abnormal. For some brands of screens, the damage of one COF will affect the display of the whole screen.
Driver board and T-CON board issues: The timing controller (T-CON) or driver boards manage the image data sent to the LCD panel. Failure can cause a black screen or lines to appear on the screen, distorted images, or incorrect colors and contrast.
☆☆☆Pixel defects☆☆☆
Individual pixels or groups of pixels can fail, creating visible imperfections on the screen.
Dead pixels: A dead pixel appears as a permanent black dot. This is often caused by a transistor failing to supply power to the liquid crystal cell and is a permanent hardware failure.
Stuck pixels: A stuck pixel is a single-color dot (red, green, or blue) that is always on. It is caused by a transistor that is permanently active and can sometimes be fixed with software or gentle pressure.
Mura effect: This appears as subtle, cloudy, or blotchy patches of uneven brightness. It can result from physical stress on the panel, manufacturing tolerances, or thermal degradation.
☆☆☆Physical damage and environmental stress☆☆☆
LCD screens are fragile and vulnerable to both immediate damage and long-term degradation.
Impact damage: The most common cause is physical impact from a drop or bump, which can crack the delicate glass substrates of the panel. This leads to spiderweb-like patterns or “ink” spots where the liquid crystal has leaked.
Internal pressure: A swollen battery in a laptop or phone can exert internal pressure on the screen, causing bright spots, bruising, or misaligned images.
Environmental factors: Extreme temperatures (heat and cold), humidity, and direct UV light exposure can degrade the materials and accelerate aging. High temperatures also exacerbate image retention.
Image retention (ghosting): Leaving a static image on the screen for a long time can cause a temporary “ghost” of that image to remain. Unlike the permanent burn-in seen on older displays, this is usually temporary for LCDs and can be reversed.