That does not rely on folk having basic skills. BEFORE I SHARE A LINK ABOUT REPAIR: TRY THE FOLLOWING. Power all devices down. Now unplug one end of each HDMI connection. Then unplug all devices from the wall power source for a few minutes.
Here's why. HDMI has a handshake system and you can see this blink as it handshakes. Some HDMI chips seem to do this and to reset those chips you have to do the above, wait a few minutes, hook it back up and test.
Self repair? Try https://www.shopjimmy.com/tv-repair-tips
My view on repair is to always get the service manual and have the background and gear to do the work.
I'm having the same problem apparently lots of others are with their LG's. Just over a year old, screen flashes for a fraction of a second every 2-3 seconds, blank the rest of the time. Sound stays on continuously. TV works fine otherwise.I was able to plug in an antenna, scan for channels, etc. The simplest fix I've found online - unplug tv, hold the power button on the remote 10 seconds, plug back in and turn off power saving mode - did nothing. I've seen comments about replacing various boards and light strips. Is this something a relative novice could handle, and if so, does anyone know of a tutorial to walk me through it? Thanks!