Laptop keeps crashing, monitor shows static

I think I posted this in the right place..

But around 6 months ago, I accidentally dropped soda on my laptop keyboard, frying my motherboard. I had to get my motherboard replaced, and everything seemed to work fine; but every now and again (every 2 hours? temperature related) my laptop crashes and do you know when you turn on television that's not connected to anything? The static image that shows? That's what happens.

I think it's a problem with my graphics card but I'm not so sure. The monitor freezes, or instantly cuts out showing the static. I know it isn't a driver issue, but what's going on?

I'm just fed up with this, I've been dealing with this laptop for 6 months with these constant crashes, can anyone help?