Diagnosing a mother board

Not sure why you think it's the motherboard. My first guess would be the LCD itself, I would test the monitor on a different computer if possible. Could also try using different cables and reinstalling the graphics drivers.

oops, just realized this is in the laptops and notebooks section. Anyway, you could still reinstall graphics drivers. Also, you can try sending video out to another monitor to see if the problem persists.