Try the old channel 3 since your set has a tuner. https://www.cnet.com/products/lg-42pa4500-42-plasma-tv/specs/
I am trying to connect my old NES system to my LG 42PA4500 plasma tv using the audio and video cables. The tv recognizes the presence of an input but says that the format is invalid. I've tried changing various input parameters relating to resolution but cannot find a solution. Has anyone any idea of what my problem might be?