Agreed. If you are looking to buy a de-cased replacement screen alone (to offer most flexibility in mounting space) then you are going to have to work out how to power and interface the screen correctly. You may do better to find one that is designed to stand alone (or at least is a self-contained unit with it's own casing and bezel) as at least it will likely have a familiar composite or s-video connection for the display itself. With most you will likely have to hard-wire the power to a 12v DC source (it may be too much for the main PC to run, but another PC power supply will simply do it) but that's smple enough.