The screen might switch off automatically if "Signal Loss Timer" is set to anything but "OFF" and there is no valid signal presented on the screen's enabled source input. Another possibility is a wrong installation that causes heat - operating ambient temperature might not exceed 40°C / 104°F. When placing the power adaptor in a fully enclosed space, make sure the air flow around the sides and top of the power adaptor is not restricted. Power adaptor needs to have a "free space" of at least 100mm all around for DC 12V models and 200mm all around for DC 24V models. If both is not the case in your situation please contact ad notam's support.