"Component-level maintenance first season - LCD TV repair case highlights" - Home Appliances

This is a 19-inch TCL TV, and the customer reported an issue.

There are many possible causes for no image: high-voltage board, logic board, motherboard, or screen. The boot sound is normal, so the CPU is functioning properly. After disassembling and testing, the high-voltage board wasn’t working when powered on. I usually check the high-voltage board by measuring its power supply, checking the STB level, and using a multimeter to test the high-voltage transformer. If the hand moves slightly, the transformer is working. Otherwise, there might be a protection issue due to aging, cracking, or a faulty circuit. I located the STB port on the high-voltage board and checked the power. When the power button was pressed, the red light turned green, indicating the power supply was normal. However, the backlight didn’t turn on, and the STB port remained in standby mode. This narrowed down the fault to the motherboard. By tracing the STB port, I found a 472 resistor connected to 12V. The voltage at this port was around 9V, but the transistor should pull it low. After testing, I found that the NPN transistor had lost its amplification capability. Replacing it fixed the issue.

Summary: Even though this was my first time encountering this problem, understanding the principle and careful analysis led to a solution. Persistence and adaptability are key in repairs. Final charge: Red, Black, Brown

Chuangjia LCD32HD30, power light turns on but the TV doesn’t start. I saw this brand for the first time, but I managed to fix it.


Before disassembling, I thought it was a bad power supply capacitor. But after checking, I couldn’t find any issues. Then I noticed that the power light turned on, but the remote control didn’t respond. I measured the voltages—5V, 3.3V were normal—but the power-on signal was missing. After further checks, I found that the power-on button voltage was only 1.4V instead of the expected 3V. Replacing the power button solved the problem.
Final charge: Yellow, Black, Brown

An electrician brought two Changhong LT26518 TVs for repair. One had a white screen, the other showed noise with low brightness. They had replaced the high-voltage board, motherboard, and cables, but the issue persisted.

The screen was integrated with the logic board, making replacement difficult. After disassembling, I found that the 3.3V voltage was only 1.7V, which pointed to a faulty capacitor. Replacing it with a 103 capacitor resolved the issue. For the second TV, the VGH voltage was too low. Tracing the circuit, I found a blown 82Ω resistor and replaced it, restoring normal operation. Final charge: Orange, Black, Brown
Konka LED32HSOS, no power. The fuse and switch tube were intact, but the secondary side had no output. Most likely, the power IC (model 6575) was damaged. Replacing it fixed the issue.

Also check the current limiting resistor, rectifier, and 50V 47uF capacitor. Final charge: Orange, Green, Brown
Skyworth 32L16HR. The TV would sometimes boot, sometimes not. After checking, I found some capacitors had degraded. Replacing them helped, but the issue persisted. Eventually, I realized the program memory had a broken connection. After re-soldering, the TV booted normally. Final charge: Yellow, Black, Brown These small faults may seem simple, but they often take hours of troubleshooting. Every repair is a lesson learned. As someone once said, “One minute on stage, ten years of work.” Success comes from hard work, persistence, and never giving up. No matter how many times you fail, keep trying—you’ll eventually succeed.

Vision SE

Vision SE is our specialist vision solution offering a wide range of classification services. Through advanced image processing, we realize professional-level visual technology, which is suitable for medical image processing, scientific research and other fields. We focus on performance optimization to make it an industrial-grade solution that is widely used in factory automation and high-demand application scenarios. At the same time, we pay attention to data security and privacy protection, ensuring that the highest standards are met when processing images and data. Vision SE's classified services exceed expectations, providing high-performance and professional-grade vision solutions to various industries.

vision services,vision sensor,vision sense,vision se,vision se review

Ningbo Autrends International Trade Co., Ltd. , http://www.visionsemr.com