We have 3 toshiba model 19sl41ou TV's that we are attempting to use as Menu Screens with the media player and a USB jump drive. Typically the menu consists of 1-2 slides. The slide loads fine on the screen but the TV ends up turning off after a short period of time (30 min or less). Is there something in the settings that we need to change in order for the TV to stay on for an extended period (4-5 hours on average)? My best guess was that I inadvertently played one slide on slideshow mode and it turned off after the slide show was finished and dormant for a short time.
There are three features on that TV that relate to shutting down automatically - sleep timer, automatic shut down, and no signal power down. They are described on pages 47 and 48 of your user's guide, available here. Try disabling one or more of them. My guess is that the no signal power down feature is the one giving you problems.