Monitor

[Fans]

On a 23" monitor, about 3 years old, some weird lines started to show up recently. On the left and rifght side. From light grey to dark grey, thinner or thicker. Lately there have been some short power cuts and vry strong fluctuations, and i didn't connect it to the ups. Only the comp is linked to the ups.

Anyone knows why these lines show up? It's a Philips, good quality, it's unexpected to have something like this after 3 years. Could it be the power or something else? Thanks