That's possible. My suggestion would be to test that by plugging the laptop in to an external monitor, if you have that option. I replaced the screen inverter on my Toshiba and the screen did the same thing before and after replacement. It ended up being a short in my motherboard that caused the issue, and the laptop was basically toast.
If you plug the computer in to an external monitor and it runs fine, then chances are you got either a bad inverter or just a bad connection either in the screen or going to the motherboard. If you plug it into an external monitor and the computer starts to act whacky after several minutes...you might have issues with the motherboard.