LCD Display Issues: How to Troubleshoot the LCD Module?

Liquid crystal display modules are used in many places and are widely used. But do you know that when a qualified liquid crystal display module is in use, it sometimes fails due to unreasonable use, unsuitable conditions, unqualified accessories, or improper installation methods. The reasons for lcd display issues and troubleshooting methods are as follows:

1. Elimination of irregular and abnormal display of the liquid crystal display module

The reasons for the chaotic display may be: the back electrode is suspended, the drive is DC, the power supply fluctuates, the contact is poor, the battery is exhausted, etc. It can be ruled out according to different reasons.

2. Elimination of the vague display of the LCD module

After assembly, the pen segments that should not be displayed are also faintly displayed, so that they cannot be read. The reason may be: the lead is not clean. Wipe it with a dry muslin cloth.

The weather is too humid and the glass surface is conductive. It can be restored after the room is dry.

The common electrode or segment electrode is suspended and can be eliminated after reliable reinstallation.

The upper and lower amplitudes of the AC square wave are asymmetrical, resulting in unclear cutoff when extinguished. Adjust the amplitude of the square wave to solve it.

If the conductive rubber strips are not correct and the insulation performance is poor, just replace the conductive rubber strips.

3. Elimination of poor contrast of LCD module

The contrast of the LCD display module is very poor, or negative image appears, or the display is chaotic, or all displays are generally caused by the suspension of the back electrode, which can be eliminated.

4. Elimination of intermittent display of liquid crystal display module

The function is disordered, cannot be adjusted, and the display is intermittent. The reason is that the power supply voltage is abnormal and the battery is exhausted, and the battery needs to be replaced at this time.

5. Elimination of the chaotic display of the LCD module

External interference may also cause confusion in the LCD module, just remove the interference.

6. “Handwriting” excluded from LCD module

After a few hours or days of use, the electrodes change color and appear black or brown “writing”, and the liquid crystal cell produces bubbles, which makes it impossible to display. This is because the direct current component of the driving voltage is too large, which causes an electrochemical reaction. Check the circuit, remove the excessive DC component, and replace it with a new LCD module.

When the “writing” just appears, the liquid crystal display device can be heated to above the storage temperature, even if the display surface of the liquid crystal display module is all black, stop heating, and after natural cooling, the “writing” can generally be removed.

7. Elimination of all the display of the liquid crystal display module

The decoder is normal, but all pixels are displayed. Generally, the back electrode is not connected properly, or the back electrode is connected to DC.

8. The reasons for the lack of stroke display of the LCD module and its elimination

The electrode leads and conductive rubber are dirty, causing poor assembly contact. The above two items only need to be reassembled after cleaning.