Devon Classen since you have sound but no picture and since it is an LG you want to check the backlight. In a darkened room and the TV on a channel that has sound, shine a flashlight beam at an angle against the screen. See if you can make out shapes or silhouettes etc. If so it’s your backlight. Check all your inputs make sure that everything is properly connected. You should also disconnect everything from your TV and unplug the set. Then hold the power button depressed for something like a minute. After that connect one video input (preferable local like DVD/BR/ or even game console) and then plug the TV back in. See if it now displays a picture.
IF none of this works you will have to remove the back cover from your TV and check the boards. Check the T-con board for power and the voltages coming of your power board. WE would need to see the boards to help you with that. Post some good pictures of the boards etc.,with your QUESTION [guide|21499]