Some time ago, I assisted a friend in fixing an LCD monitor that developed horizontal lines on the screen before they purchased another one. They were convinced the monitor was defective, but we started checking through the quick fixes (i.e.: Checking that both ends of the cable were connected) and upon checking the HDMI cable between the monitor and the computer, it was discovered that the HD-Mi cable was loose since their desk was recently rearranged. Once that Cable was secured, the lines vanished.

For this reason alone I recommend starting with simple fixes first. Check cable connections, reboot the computer and if possible, test another monitor with the same video Card and see if it works fine. If there were any issues with each fix, then it is worth pursuing driver and/or damage to the video card. Sometimes the simplest problem, turns out to be the cause of the overall problem.