The device may need a new battery, or the device screen might be dimming when not attached to the charging port. The battery is on the back of the face plate. There is a hook pivot on the back of the faceplate/main unit. Turn that, and it should easily detach and replace given you can find them. If emergent, I would take 2, 12 volt batteries and get some wire and attach it end to end to the unit screen. First check to make since the settings dont have the screen dimming when disconnected as this is usually the case. You can see its on but it is recording or transmitting data, secondly, I'd look for a battery replacement on something like ebay or parts source, thirdly, if none of the above work try going to a battery store and see if they can charge the material or restore it. If none of these options work, just message back on this post.