I have a Samsung Syncmaster 920NW monitor that turns off after 3 minutes. Any idea how to fix it?

The monitor is just about 1 year old. 19 inch. It works perfectly for about 2 to 3 minutes and then shuts off. I tried dimming the screen to see if it was heat related but could not see any effect. If I turn it off then on, it will run for about 10 seconds. The resolution is great – when it runs. Is this a common problem? Any idea on how to fix it? It is very frustrating.