Changhong LCD TV TL19629 power failure repair example - appliance repair - Huaqiang electronic network

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I recently worked on a maintenance task for a Changhong LCD TV model TL19629, where the power supply had a serious issue. The power board was heavily damaged, and after carefully removing the circuit board, I noticed that many of the chip resistors were burned beyond recognition. Unfortunately, the online schematic drawings didn't include component values, so I had to rely on the FET circuit design to estimate the correct resistor values for the perfusion board and fill them in accordingly. To prevent the same failure from happening again, I used an external 5V power source during testing. I checked the voltage regulator section and the optocoupler, which both appeared to be functioning normally. I also measured the driving waveform without the power transistor installed to ensure everything was stable before proceeding. Once everything looked good, I installed the power transistor. After powering up the unit, the power board returned to normal operation. I've now filled in the resistor values for the perfusion circuit, and I'm sharing this information for your reference.