Lg Tv Hdmi Ports Stopped Working. If after performing a hard reset on the tv and replacing the hdmi cables, you still have this issue, i suggest to replace your lg tv main board. Try a different hdmi input:

However, you can use the component inputs (5 wires, green, blue, red, white and red) instead of the hdmi input to bypass the problem. I have had a on going problem with the hdmi port failing after about three weeks. I have an lg 55c oled and the hdmi inputs won’t work.