U2312HM, Blue Line Showing

I purchased a Dell U2312HM Monitor in March earlier this year for school. This morning I went to turn it on, plugged everything that needed to be plugged in, for me to use it with my laptop, and I see this blue line going down on the left hand side. I have two of these monitors and the other one is fine. I don't know what could have happened because I haven't used them much this summer (since there's no school) - maybe 5 times at most. I tried doing a power reboot and doing a factory reset but nothing has worked. Does any one know what else I can do? Seeing as I purchased this literally 6 months ago, I am covered under warranty right?