Just a guess here, but are you sure it was the keys that did it? If he was on the keyboard, he may well have brushed against the controls on the monitor itself. Play with the knobs on the monitor itself and see if it fixes it.
I offer this because I worked at a credit collection agency, and at least 3 times a week someone came up to me with the "my computer is broken, it won't turn on!" problem. 70% of the time, the correct solution was to turn the brightness knob that they had somehow spun all the way down, up. The other 29% of the time was to plug it back in after they'd kicked the cord out of the wall.
Qwinn
I offer this because I worked at a credit collection agency, and at least 3 times a week someone came up to me with the "my computer is broken, it won't turn on!" problem. 70% of the time, the correct solution was to turn the brightness knob that they had somehow spun all the way down, upIt's too bad some people don't come with those. (Or for that matter "mute" buttons.)
-Eric