LCD display module white screen no display
At present, many display devices use LCD screens, and during use, you may occasionally encounter a white screen with no display. What is the reason for this phenomenon? How should it be solved?
1. The white screen does not display the corresponding product type
TFT LCD / monochrome LCD liquid crystal module with single-chip microcomputer interface, especially for single-chip single-chip microcomputer interface LCD display products.
2. What is a white screen with no display
No display on a white screen means that the LCD display changes to a blank screen with no display under (suspected) external interference; when there is no display on the white screen, the system is still working normally; shutdown and restart or system reset can return to normal.
3. Why is there a white screen with no display?
White screen without display is generally the state of off display, and it is also the default state of reset/startup of the LCD display module. When the LCD display module receives a restart command or reset signal, it will return to the default state, resulting in an empty screen with no display.
Possible Causes and Solutions of LCD White Screen
1. The reset signal of the LCD display module is left floating
In design, the input port of the module should not be left floating, and the reset signal is also an input port. The relevant interface is preferably connected with the single-chip microcomputer, and is directly controlled by the single-chip microcomputer.
2. Poor interface contact
Need to pay attention to the reliability of the signal connection.
3. The host sends a reset signal by mistake, a reset command or a command to turn off the display
Need to trace the program flow to find out the key points.
4. The related white screen is usually found in the interference test (eg: electrostatic (ESD) test)
In general product design, the display module is placed in front of the product; external ESD will expose the display module to the relevant electric field; interference may not directly affect the signal or reset. However, related interference can easily affect 0V or power supply, causing the LCD display module to misjudge the signal voltage; shortening the wiring distance between the host and the display module has a certain effect, and adding resistance/capacitance to the reset signal connection can also improve the related situation.
5. Other options
In the face of unknown interference that may occur on site, it is recommended to periodically refresh the display content and related screen initialization settings to improve/recover abnormal display conditions caused by interference;
When the interface menu jumps back to "Home", it is generally a full-screen refresh. You can consider re-swiping the relevant screen initialization settings during this process to ensure that the display module settings are correct;
Considering that the reset default is "off display", the microcontroller can also read back the display status periodically to know whether the LCD display module is in a normal display state; if an abnormality is found, the host can issue a hard reset, re-initialize the LCD display module and refresh the display content, to ensure normal display.
The LCD display module is a slave device and obeys the input commands and signals; the LCD display module has no ability to judge the correctness of the relevant input; a good power supply and a reasonable wiring layout are the basics of a good display; the monitoring and compensation of the software can be further improved System guarantee.