No picture or sound after changing the main board.
Hi, I have an LG55UJ634V tv that had a blank screen. All that came on was the red standby light that blinked 3 times. I have replaces the main board and now the screen powers up but no picture or menu display appear. The screen is on but blank.
@johnnystorm measure the voltages from the power board to the main board and let us know what those voltages show. Check on the fuse at the t-con board and let us know what voltages you get on that. From what you are saying the backlight turns on but no video which should be generated by the main board. Post some pictures of all of your boards and the interconnect cables with your question so we can see what you see.