Most of our computer labs now have the NComputing L300 thin client units. These are a diamond-shaped box attached to the back of the monitor. They are connected to a server and that is how you are able to use this terminal-type device as a computer. If you see the message on the screen that says "Cable Not Connected", it usually does not mean there is a loose cable. What the monitor is trying to say is it doesn't have a signal. This message often displays when the unit on the back of the monitor goes to sleep or when you first turn the monitor on and it doesn't see a signal because the unit is asleep or turned off. If you pick up the mouse and see a light, this means the unit is on and likely asleep. If you move the mouse or press a key on the keyboard, it should wake up. If it does not have a light, the unit is most likely turned off. There is a power switch on the unit that is located on the left side where you can turn it on. Sometimes, the unit won't wake up from sleep. If this happens, you can turn this power switch off and back on again. You should see the unit booting and within about a minute, it should be at the desktop or login screen. If it still won't work, go ahead and check the cables. Sometimes a student will kick a power cord out or they will inadavertently come loose.