Can a faulty driver board cause a white screen when the LCD screen is turned on?
Date:2026-01-13
A faulty drive board (also known as the mainboard/control board) is one of the most common causes of a white screen upon startup of an industrial control LCD screen.
This is different from the root cause of the "black screen" issue previously discussed. Simply put:
Black screen is often related to the backlight system (either the backlight itself or the backlight control circuit of the driver board).
A white screen is almost certainly related to the image signal processing system (driver board, cable or LCD panel).
A faulty drive board (also known as the mainboard/control board) is one of the most common causes of a white screen upon startup of an industrial control LCD screen.
This is different from the root cause of the "black screen" issue previously discussed. Simply put:
Black screen is often related to the backlight system (either the backlight itself or the backlight control circuit of the driver board).
A white screen is almost certainly related to the image signal processing system (driver board, cable or LCD panel).
If these two types of instructions are completely missing or severely abnormal, the liquid crystal molecules cannot deflect correctly to control the passage of backlight. In the default state, all backlight will pass through, and the screen will appear as a "white screen" or "gray screen" with backlight on but no image.
Common driver board failure points leading to a white screen
When a white screen appears, the following parts of the driver board should be inspected with emphasis:
Faulty component | Failure cause and phenomenon |
The main chip is damaged or has poor soldering | The main chip serves as the "brain" of the drive board. Damage or pin desoldering caused by long-term exposure to high temperatures, vibrations, or static electricity can directly lead to its inability to process signals or output commands, resulting in a blank screen. |
Core power supply circuit fault | The DC-DC circuit that supplies power to the main chip and logic board (such as generating voltages like 3.3V, 1.8V, etc.) is damaged. Without power, the chip cannot operate, inevitably resulting in a white screen. |
Screen cable interface or circuit problem | The interface on the drive board that connects to the screen cable is loose or oxidized, or the resistor and fuse connected to it are damaged, resulting in the signal not being transmitted to the screen. |
Program (firmware) corruption | Abnormal power loss or other issues may cause the memory program on the driver board to become disordered, preventing the chip from initializing normally. This often manifests as a white screen or a white screen after a distorted screen. |
Image input interface failure | Although uncommon, damage to the analog/digital conversion circuit following input interfaces such as VGA/DVI may also prevent signals from entering the processing flow. |
Systematic troubleshooting steps (focusing on white screen)
You can quickly locate the source of the white screen issue by following the steps below:
Specific operation instructions:
1. Step 1: Basic inspection (the simplest yet most important)
Operation: In the case of power failure, reseat the screen cable (usually a flat cable) between the drive board and the LCD panel. Check the cable and interface for oxidation and bending.
Objective: To eliminate poor contact caused by vibration, thermal expansion and contraction, which is a very common reason in industrial control sites.
2. Step 2: Measurement of key voltage (core diagnostic step)
Operation: When powered on, use a multimeter to measure the key voltages outputted by the drive board to the LCD panel (logic board). There are usually test points near the screen cable interface, with common voltages being 3.3V, 5V, 12V, etc. (varying depending on the screen). Refer to the screen's specification sheet for details.
judgment
If all these voltages are normal, the fault may be due to damage to the main chip of the drive board, a program error, or damage to the logic board of the LCD panel itself.
If a certain voltage is abnormal or missing, the fault will be locked on the corresponding power supply circuit of the drive board (such as voltage regulator chip, filter capacitor, inductor, etc.).
Maintenance decision-making suggestions
Based on the investigation results, you can make the most suitable decision:
Fault localization | Possible solutions | Applicable situations and descriptions |
Poor contact of the flat cable | Clean the interface and replace the screen cable | The one with the lowest cost should be handled first. |
The power supply circuit of the drive board is damaged | Repair or replace the drive board | If you have electronic repair capabilities, you can try replacing the damaged capacitor and voltage regulator chip. Otherwise, it is recommended to replace the entire board. |
Main chip or program issue of the drive board | Replace the drive board or flash the firmware | Replacing the entire board is the fastest and most stable solution. Updating the firmware requires professional equipment and files. |
Suspected LCD panel malfunction | cross-testing | Connect the drive board of this device to another good screen of the same model for testing. If the good screen also displays a white screen, it confirms that the drive board is damaged; if the good screen works normally, it indicates that the original LCD panel is damaged. |
Summary: When facing a white screen, first check the screen cable, and then focus on measuring the voltage output from the driver board to the LCD panel. The probability of a white screen caused by a driver board failure is much higher than that caused by a failure in the LCD panel itself.
If you have already undergone some examinations, you can tell me more details, such as:
Has there been any change after reseating the screen cable?
Is it possible to measure the voltage or detect any abnormal noise (such as slight howling) on the motherboard?
Did the white screen appear suddenly, or did it occur after the device was vibrated, relocated, or abnormally powered off?
This information can help further narrow down the scope of the fault.
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