After the boot, found no image, there is sound. Open the back cover, boot check, no plug antenna, found the image came out, there TCL trademark, that TV is good, plug in the antenna, and no image, and think of the circuit as if there is a problem, Voltage, 1.5V1.1V0.9V. Obviously not normal, according to experience, for the three C4544, or not There are good, but also check the other places as the board, or not repaired. OM8838 Weld place, all repair welding again, or not good. Increase the acceleration potentiometer, there Hui-line, analysis ABL circuit problems will also be a black screen problems, check the capacitor C421 Weld, welding after the image is not a black screen, but there is a white screen, and finally found As the OM838 26 feet voltage increased to 1.2v, 26 feet is the internal RGB electronic switch, the normal should be low. Off 28 foot test, 28 feet about 3V, for the OM8838, the image is normal. Then can not figure out why bad before, there will not be a white screen problem, but also put the original machine OM8838, after the boot image is normal. I think the user may be the lack of brightness, in the welding OM8838, there was a short circuit.Ja4service manual download site