computer problem

OK, my grandmother's computer monitor, a Dell flat-panel, keeps going completely white on her. The hard-drive is a Dell, also. I think she's only had it a little over a year. We have changed the surge protector and it still goes white on her. All you see is a white screen. It does it randomly and you never know when it's going to do it. She asked me what's wrong with it and my only thought was that it's "lightbulb" was going out or the connector/power cord that's physically attached to the monitor is bad.

What do ya'll think?