A power supply board is a circuit board primarily responsible for power processing. The power processing methods vary depending on the requirements of subsequent circuits, such as: input/output types: AC, DC, pulse, high voltage, low voltage, high frequency, low frequency, single channel, multiple channels, etc.
Troubleshooting methods for power board failures:
1. If pressing the power switch of the TV does not respond to the buttons and the TV indicator light flashes, and the power board circuit output is normal when tested with a multimeter, and there is no current output from the main power supply, then the button board is not faulty.
2. Disconnect the power supply line from the power board to the motherboard, force the power board to start, and if the power output of each circuit is normal as measured by the multimeter, it indicates that the power board is working properly.
3. Correctly select the TV screen cable. The blue and white signal cables are in pairs. Use a multimeter to measure the screen cable.
4. After confirming that the screen cable is correct, use the power detection tool to turn on the TV and observe the TV screen. There is no image displayed, the TV backlight is on, and the TV screen is gray.
5. Using a multimeter, it was found that the power supply to the TV screen was normal, but there was no voltage after passing through the fuse. After the power was turned off, the fuse was found to be open. Replace the fuse.
6. After replacing the fuse, the TV still had no picture. After upgrading the TV program, there was still no picture. Using a multimeter to measure various test points on the logic board, an abnormality was found. After replacing the DC chip, the TV voltage returned to normal, and the screen started displaying an image.
7. After reconnecting all the wiring to the TV, plug in the power. The TV indicator light will turn green, and the TV screen will display snow while there is sound.
8. If the LCD TV image is normal after the TV video signal is added, the fault has been resolved.
