Skyworth LCD TV 20L98TV has sound no image repair record - android - Phones Developers

SMD aluminum electrolytic capacitor

DFN1006 TP-RCLAMP3321P ESD Diode Low Capacitance

Chip ceramic capacitor

Patch Murata capacitor

I saved a screen again! Skyworth 20L98TV repair record. One morning a few days ago, I received a customer call and said that a TV was broken. I asked for a door to repair. I asked the customer how much TV, what brand, and I didn’t know. I only said that TV had been bought for several years. Thousands of dollars, now there is no sound, no image, hanging on the wall, I heard, I thought it was a big guy, drove to the car, opened the door is a 60-year-old uncle, enthusiastically led me to the room Pointing at a 20-inch Skyworth TV on the wall, good guy, I thought it was money. This is the old 20L98TV TV. The heart is cold. If you come, you can take it for work, or you have to pay for it. The test machine has no picture, and there is a little gray-blue background on the screen. If the case is opened, the backlight is bright, and the power supply on the power board and the motherboard is normal. It is normal to measure the 5V power supply on the screen. Dabo said that a few days ago he called a repair to repair, pointing to the main board and said that the master changed the board, the fault is still the same, that the screen is broken, to change the screen, the price is very expensive, call him There is no need to change the screen, now it is worthwhile to buy a new machine... Class... He said that a friend said that I would fix the screen... I gave him a funny saying that repairing the screen is risky, just like a doctor giving a big operation to a patient. By life, although I don't call you a signature guarantee like a hospital, but the ugly words are said to be in front, if there is anything wrong with the loss, the dead horse is a live horse doctor, the machine pulls back to repair, and the price is good, the old man promises to take the machine. The trunk of the car is ready to leave...
At night, go home and open the machine, fold a fine light, this piece of AU screen, a201sn02 screen, use 5V to supply power to the on-screen logic circuit, open the iron cover on the logic circuit on the screen, connect the power board and the motherboard, power supply and test power supply 5V is normal, measuring several voltage key points: VGL, -6.2V VGH, 24V, VCOM, 6.5VVCC, 5V other groups of voltages are basically normal according to the data, unplug the screen line screen is bright, plug the screen line gray screen bright From the light and dark changes, some signals or integrated chips of the logic circuit are not working or not normal. Because there is very little information on the logic circuit in the screen, the pin data of each integrated circuit need not be said, and it is impossible to check the order. Yes, I drank a cup of tea, and the machine was always open. Go back and check it. The hand touch screen is a little hot, and the heart suddenly has a flash of light. Try it with the temperature method, so power off, use one by one. To feel the temperature of the logic board in the screen, when the hand touches an integrated chip called AS34-G, the hand instinct shrinks, the hot can't stand it, is it..., so the screen is completely cold to normal room temperature Plug in the test again, less than a minute, the temperature of other parts is slightly hot However, the surface of the AS34-G can not be touched. First, the external components are measured. There are not many external components, several capacitors and several resistors, and only three transistors. First, several chip capacitors are removed. The measured capacity is also leaking, and the triode is measured without any problem. Several resistors have been measured and no abnormalities have been found. It is determined that the AS34-G is bad. I am eager to take a few AS34-G on a certain treasure. Arrived, changed a test machine, the miracle appeared, and another screen was resurrected!
Passed a few pictures of the repairs that I took, I am a rookie, the theory is not half a bucket of water, the experience has been in the touch, welcome to shoot bricks!