NEWS

LCD White Screen Causes and Solutions

09.25.2023

In the process of using the computer, you will encounter a black screen, blue screen, splash screen failure, often use the computer friends are familiar with, in fact, there is an unusual white screen phenomenon, some users may have encountered, LCD white screen mainly appears in some of the longer use of the monitor. LCD white screen how to do it? How to solve?

Why is the LCD screen is a white screen?

1. The LCD white screen may be due to poor contact or damage to the video card or video cable.

2. The display internal problems are mainly: LCD panel driver circuit, LCD panel power supply circuit, screen line poor contact, the main board control circuit.

As the LCD screen is white screen after power on, which means that the backlight and high-voltage generation circuit work normally, but the LCD panel does not get the drive signal. If the screen disappears after the computer is turned off, and then the screen becomes white again, it may be caused by power board problems.

3. From the analysis of the failure phenomenon, whether on or off, as long as the LCD screen plugged in, the high-voltage generation circuit is always in working condition, the backlight is always on. In other words, the high-voltage circuit is not controlled by the switch, that is, the motherboard sent to the high-voltage circuit switch signal out of control. As the motherboard microprocessor to send the switch signal is generally controlled by several transistors, so the failure may be caused by damage to the control switch signal transistors.

How to solve the LCD white screen problem and maintenance ideas?

First of all, rule out the problem is the graphics card or VGA line problems, change a VGA line to see if it is still a white screen. If the screen is still white, that is the problem of the computer host, most of them are poor contact or failure of the graphics card, but this rarely happens. The following details of the solution to the phenomenon of poor display resulting in a white screen:

1. First disassemble the shell of the LCD screen, and then check whether the screen interface is loose or incorrectly connected, check the shield line is connected properly, continue to the next step.

2. Open the computer's power switch, and then use a multimeter to measure the screen interface power supply voltage is normal. If the supply voltage is normal, go to step 5; if abnormal, check whether the safety resistor or safety inductor near the output of the shield line is open or damaged, and if damaged, replace the damaged components.

3. If the safety resistor or safety inductor near the output of the screen line is normal, check whether the voltage at the output of the DC-DC voltage conversion circuit supplying power to the LCD is normal. If the output voltage is abnormal, check the safety resistor, PWM controller, switching tube, inductor coil, filter capacitor and other components in the power supply circuit, and then replace the damaged components.

4. If the output terminal voltage of the DC-DC voltage conversion circuit is normal, there are damaged capacitors and other components between the output terminal of the DC-DC voltage conversion circuit and the screen interface, check and replace the damaged components.

5. If the screen line interface supply voltage is normal, then check the timing signal in the LCD panel driver circuit, whether normal. If not normal, then check the output signal, the input signal and the power supply voltage of the chip that generates the signal to determine whether the driver chip is damaged. If damaged, then replace it.

LCD white screen maintenance is not as easy as black screen, blue screen, it is necessary to master some knowledge about the circuit of the display, it is best to send the display to professional institutions, ask professional display maintenance personnel for maintenance. In fact, when you encounter LCD white screen failure, do not think that the display is not fixed, sometimes the fault is very simple, easy to repair, repair staff to repair the sentence of its "death penalty" is not too late.