I hear a lot of talk about accumulated hours. I recently bought a used/seller refurbished toughbook (typing on it right now actually). It sees to have no issues and is working perfectly fine. I checked the accumulated hours and seems to be about 27,500. However, I heard that it doesn't matter much for a CF-31 because the screen is powered by an LED backlight and even CF-30's themselves (which have an earlier wearing CCFL tube) do well to 50,000 hours and beyond.