What to do if your TFT industrial LCD screen goes white? How to repair an LCD screen?

An industrial LCD screen suddenly turning white is an “emergency” that every equipment maintenance worker has likely encountered. A white screen is a common malfunction in industrial control equipment, CNC machine tools, or self-service terminals. A white screen doesn’t necessarily mean the screen is completely damaged; it’s often caused by abnormalities in power supply, signal transmission, or control circuitry. Blindly replacing the screen not only increases costs but may also only address the symptoms, not the root cause. A white screen usually means the backlight is working normally, but the image data isn’t being transmitted or processed correctly. Unlike a black screen, which indicates a complete power outage, this makes the problem more perplexing. From a professional perspective, white screen problems can usually be systematically troubleshooted from four aspects: power supply, signal, hardware, and software.

Power Supply and Power Consumption: Check if the cables are stable

Although a white screen indicates the backlight is on, it doesn’t mean all power supplies are normal. The LCD screen‘s driver board and logic circuits require stable and precise voltage and current.

Troubleshooting Solutions

Check Power Supply Voltage: Use a multimeter to measure the power supply voltage of the LCD screen driver board (usually 5V or 12V). Low voltage or large fluctuations may cause malfunctions in the logic circuitry.

Confirm Power Supply Interface: Check if the power supply interface is loose or has poor contact. In vibrating industrial environments, connectors may become detached due to vibration.

Check Power Adapter: If the device uses an external power supply, try replacing it with a power adapter that matches the power and voltage to rule out the possibility of the power supply itself being old.

Signals and Cables: The “Highway” for Data Transmission

One of the most common causes of a white screen is interrupted or incorrect signal transmission. This is like data packets being lost or corrupted during transmission, causing the LCD screen to be unable to correctly interpret the image.

Troubleshooting Solutions

Reconnect and Unplug Cables: First, after powering off, carefully reconnect and unplug the LVDS, eDP, or TTL cable between the motherboard and the LCD screen. Ensure both ends of the cable are firmly and securely plugged in, without any misalignment or looseness.

Inspect the ribbon cable appearance: Carefully inspect the ribbon cable for obvious creases, damage, or breaks. If the ribbon cable has physical damage, it must be replaced.

Inspect the interfaces: Observe the gold fingers of the interfaces on the motherboard and LCD screen for oxidation, dirt, or signs of burning. You can gently wipe them with anhydrous alcohol and cotton swabs to remove dirt.

Hardware and Drivers: The “Brain” and “Nerves” of the LCD Screen

If power and signal transmission issues have been ruled out, the problem may lie at the hardware or driver level.

Troubleshooting Solutions:

Replace the driver board: If your TFT industrial LCD screen uses an external driver board, try replacing it with a working driver board. This can quickly determine whether the problem is with the driver board or the LCD screen itself.

Check the graphics card driver: If your device is an industrial control computer with a dedicated graphics card, check if the graphics card driver is installed correctly or if there are any conflicts. You can try reinstalling or updating the graphics card driver.

Screen driver firmware: Some LCD screens require specific driver firmware. If the firmware is corrupted or the version is incompatible, it may also cause a white screen. This usually requires contacting the supplier to obtain the correct firmware and flashing it.

Environmental Factors and the LCD Screen itself

In some special cases, environmental factors can also cause a white screen.

Troubleshooting:

Temperature Effects: If the equipment operates at extremely high or low temperatures, it may cause abnormal responses of the liquid crystal molecules inside the LCD screen, resulting in a white screen. Ensure the equipment operates within the temperature range allowed for TFT industrial LCD screens.

Electrostatic Interference: In a dry environment, static electricity may enter the LCD screen through the interface, causing damage to the logic circuit. Always take anti-static measures during maintenance.

LCD Screen Damage: If all the above methods fail to solve the problem, it is likely that the logic circuit or T-Con (timing control) board of the LCD screen itself is damaged. This usually means that the LCD screen needs to be replaced.

Frequently Asked Questions (Q&A)

Does a white screen on an industrial LCD screen mean that the screen must be replaced?

Not necessarily. In many cases, it is caused by wiring or power supply problems, which can be resolved by replacing parts or adjusting parameters.

How to reduce the incidence of white screen failures?

Selecting a TFT industrial LCD screen with wide temperature range, shock resistance, and long lifespan during the selection phase, and implementing robust power protection and signal shielding designs in the overall system, can significantly reduce the failure rate.

Summary

A white screen on an industrial LCD screen doesn’t always indicate a problem with the screen itself; more often, it’s a problem with the signal, power supply, or control circuitry. By systematically troubleshooting, the fault can be quickly identified and addressed. For equipment operating for extended periods, proper selection and preventative measures are more important than post-incident repairs. When encountering a white screen problem with a TFT industrial LCD screen, the worst thing you can do is operate blindly. The correct approach is to systematically troubleshoot, starting with the easiest steps. First, check the power supply and ribbon cables—the two most common issues. If the problem persists, then delve into the driver board and software. If all external factors are ruled out, the LCD screen itself is likely damaged, requiring contact with a professional supplier (such as LEEHON Technology) for repair or replacement.

Hangzhou LEEHON Technology Co., Ltd., as a provider of LCD display driver solutions for the industrial field, has established in-depth cooperative relationships with many leading global LCD panel manufacturers such as BOE, TIANMA, IVO, AUO, Innolux, and Kyocera, and professionally supplies multi-brand, full-series industrial-grade LCD displays and customized solutions.