I’ve had my LG 55” TV 2 years last night it started powering OFF every 5 seconds when I turned it On. I checked the power cable, disconnected all HDMI inputs (cable box , blu ray player and Echo Cube). This had no effect. I replaced the batteries in each remote control. When I replaced the batteries in the Echo Cube remote it stopped. The batteries in the Eco Cube remote were half dead which was causing the remote to send out power Off commands to the LG TV. The TV has been working fine ever since. I hope this helps.