LG webOS TVs show their own screensaver after about an hour without a remote press, and some switch off after a few hours. Here's how to keep the slideshow on screen.
LG webOS TVs assume someone is watching with a remote. After roughly an hour without a button press, they show their own screensaver on top of whatever is playing, and many models also switch off after a few hours of no input. For a sign that runs all day, both get in the way.
Tested on the LG 32LM620 (webOS 4.5).
Everything unlocked, any number of displays. No card needed.