What's the problem with the industrial control LCD screen showing a white screen at startup?

LCD industrial control LCD screen (Liquid Crystal Display) is now one of the devices that can be seen everywhere, and its use in industry has also increased with technology! Now, industrial industries have begun to use industrial control LCD screens. Although they are clear, there will always be White screen. So, how to solve the white screen failure? It is a very common phenomenon that the LCD industrial control LCD screen has a black screen or a blue screen when it is turned on. Black screen and blue screen are system or hardware problems, while the white screen failure of the display screen is generally caused by the LCD industrial control LCD screen. own fault.

1. Cause of failure:
LCD industrial control LCD screen white screen failure may be caused by three aspects: LCD panel drive circuit problems, LCD panel power supply circuit problems, poor screen line contact, motherboard control circuit problems, etc. If the industrial control LCD screen can be turned on normally, it means that the backlight and high-voltage generating circuit are working normally, which means that the LCD panel does not receive a driving signal; if the screen disappears after shutting down, and then a white screen occurs, it may be a problem with the power board.

This shows that no matter it is turned on or off, as long as the power is plugged in, the high-voltage generating circuit is in working condition and the backlight is always lit. In other words, the high-voltage generating circuit is no longer controlled by the switch, that is, the switching signal sent by the motherboard to the high-voltage generating circuit is out of control. Since the switching signal sent by the motherboard microprocessor is generally controlled by several triodes, the fault may be that the triode controlling the switching signal is damaged.

2. Troubleshooting:
1. Disassemble the casing and check whether the screen cable interface is loose or not connected properly.

2. Turn on the power switch, and then use a multimeter to measure whether the power supply voltage of the screen cable interface is normal. If the power supply voltage is normal, check whether the timing signals and driving signals in the LCD panel drive circuit are normal; if not, check whether the fuse resistor or fuse inductor near the output end of the screen cable is open or damaged. If damaged, just replace the damaged components.

3. If the fuse resistor or fuse inductor near the output end of the screen cable is normal, then check whether the output voltage of the DC-DC voltage conversion circuit that powers the LCD industrial control screen is normal. If the output voltage is abnormal, check the fuse resistor, PWM controller, switch tube, inductor coil, filter capacitor and other components in the power circuit, and then replace the damaged components.

4. If the voltage at the output terminal 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 cable interface. Just check and replace the damaged components.

5. If the power supply voltage of the screen line interface is normal, then check whether the timing signals and driving signals in the LCD panel driving circuit are normal. If it is abnormal, check the output signal, input signal and supply voltage of the chip that generates this signal respectively to determine whether the driver chip is damaged. If damaged, just replace it.