"The screen suddenly flashed a few times and the screen was black, and the border was cumbersome. Is this a leak?" The LED advertising screen that Lao Wang had just installed next door two days ago encountered this bad thing. To be honest, this kind of fault can be big or small, and there were statistics in the industry last year,23% of LED screen accidents are caused by leakage​, at the least, the control card is burned out, and at the worst, the fire is caused. Today we will talk about how ordinary people should solve such fatal problems.

1. Don’t ignore the “signal light” that leaks

Remember three red flags first:

1. ​​The screen flashes locally​: Like an old TV, the power consumption may exceed 40% at this time
2. ​​Control box is hot​: The normal temperature should be below 50℃, and it feels slightly hot when you touch it
3. ​​The trip frequency becomes higher​: Especially when the trip is frequent during rainy days, 80% of the waterproofing problem

Last week, a milk tea shop owner complained to me that the front screen of his house would automatically restart every time it rains. Later, I took a look at it,​The insulation layer of the power cord was gnawed through by mice​​, the copper wire is directly placed on the metal frame. If this situation is not discovered in time, it can cause death in minutes.

2. Don’t choose the wrong detection tool

If you want to do a good job, you must first sharpen your tools. These tools must be prepared:

• ​Digital multimeter​: Choose NCV non-contact power test function (can measure voltage in space)
• ​Thermal imager​: Rent a second-hand one for 80 yuan a day, which can quickly locate the hot spot
• ​Insulation resistance tester​: This is more professional, but Taobao has a simple version of about 200 yuan

The key point is here!​Don't use traditional electric tester​! The working voltage of LED screens is generally between 5-48V, and ordinary electric pens cannot measure accurately. A friend didn't believe in evil, but he misjudged the location of the fault and replaced three driver boards in vain.

Three- and five-step investigation method

Following this process, 80% of the problems can be found:

1. ​​Power off identity verification​: Unplug the plug first! Use a multimeter to measure the resistance of the screen body to ground, and it should be >10MΩ normally
2. ​Block isolation method​: Divide the screen into 4 areas and power off one by one to test
3. ​Check the water source path​: Focus on the power cord entrance, splicing seam, and heat dissipation hole (use flashlight to shine water stains)
4. ​​Measure insulation weakness​: Use a megohmmeter to measure the resistance between the lamp plate and the box, and it is a high risk if it is less than 2MΩ
5. ​Check the grounding system​: Many leakages are actually caused by poor grounding. The measurement grounding wire resistance must be <4Ω

Last year, the fence screen in a gymnasium leaked electricity, and finally found that it was​The drain pipe backflow causes water accumulation in the control box​​. This hidden fault was located in two hours using the blocking method.

4. Comparison table of common leakage types

Special attention:​The most dangerous leakage caused by rust in the box​, because the metal frame has a large live range, it is easy to cause chain accidents.

5. Repair or replace it?

Here is a calculation formula:​Repair cost ÷ Equipment residual value > 35%, it is recommended to replace it with new ones​​. For example, if the P4 screen has been used for 3 years, the residual value is about 4,000 yuan:

• If the repair quotation exceeds 1,400 yuan, it is better to buy a new screen
• But if you only use the new screen for half a year, you have to repair it even if it costs 2,000 yuan.

There is a bloody lesson: In order to save 8,000 yuan in maintenance costs, a shopping mall caused a short circuit to burn the entire control system, and finally lost more than 100,000 yuan. So if you need to change, don’t lose the big one because of small things.

​Editor's opinion​: Last month, I visited a display factory and found that their quality inspector actually used a high-pressure water gun to rush the seam with a high-pressure water gun for half an hour while simulating a heavy rain test. When asked why the person in charge was so cruel, he said, "The leakage accident is caused by negligence in details." Now I finally understand why some screens are so expensive that they make sense - they strangle the risk of leakage in the cradle before leaving the factory. So, when buying a screen, ask more questions about "how to do waterproof testing", which may be more worthwhile than bargaining 500 yuan.

for more product information and pricing, please contact us .