Hi, my monitor (Dell 20") has developed a vertical blue line a couple of pixels wide. This happened out of nowhere while it was in use, so it didn't get a bump or anything like that. The line doesn't appear in screenshots, so I think this means it is the monitor that is at fault not the graphics card, right? I'm using an HD4850. Does it sound like my monitor needs repairing/replacing or is there anything else I can try first?