Welcome to TF.
What did you do with it before this happened? did it just freeze? Or blacked out when using it?
I wouldn't blame the motherboard just yet.
Did you clean out your laptop at all? Clean out the vents on the side. That can be one sign of overheating of the cpu or gpu.
I had my screen on my netbook turn all different colors sometimes. I just had to do a hard shut down (hold the power button for 6 seconds), took out the battery for a few minutes, plugged it back in, push power button, everything is right as rain.