Chosen Solution
So - inherited a LG 50UH5530-UB. Symptoms, no picture, no sound, no backlight. When plugged in, and turned on, will get a very brief (less than a second) flash of the LED and the LG logo on the screen, and then completely nothing. Red Standby light will flash 2-3 times. If I try to turn it on again, i don’t get the LED Flash and logo, but I do get the three blinks on the standby light. If I unplug and let it sit for a minute, and try again, I get the LED flash and LG logo again, but then back to black, no sound, no LED backlight. Now here’s the interesting thing, I’ve replaced the power board and the main board and it’s still doing the same thing. So…Tcon board? I can’t think of what else it could be. It seems to me that if I’m at least getting that LED flash and logo, even for a brief second, it must mean the LED’s are working. Thoughts?
@billmar I recognize this is an old question. Just for completion sake. Since you already changed the main board and the power board, the only board you have left is the T-con board. The error is not typical of T-con board failure but I would now change it as well. For LG TV’s the 1-5 blinks are usually connected to a video error. If your T-con board will not resolve this you will have to try to measure the outputs to the screen.
The OP had written on another board that he had figured out that the problem was an LED strip. I have the exact same model and tested the strips: one was bad. After replacing the strip, my TV works fine.
The entire screen flashes as the power supply gives power to the less. Because the light defuses through the layers of diffusing material you will not know by looking externally if a section is bad. Also a bad led can still flash. You need to test each section. If one section flashes with test equipment but does not light up fully then you have at least one led that is not regulating and cause extreme fluctuation in power consumption forcing the power supply into protection mode.
