Problem with 2005FPW, image flickering and unreadable

I turned on my monitor today and found the image completely unreadable. It looked like an old television with the vertical hold slipping. I turned off my computer and pushed the Change Input button on my monitor. The name of the input would appear on the monitor clearly for a second, but then it would start flickering and eventually streaking all over the screen. After trying a few things, I unplugged the power cord from the monitor and plugged it back in and it seems to have fixed it for now. I'm pretty sure the power cord hadn't been touched so I'm not sure that was the problem. I'm trying to figure out exactly what happened and what I can do if it happens again.