i have been using this graphic card for about 6 months
psu - 355 W it seems my psu doesnt have the specs labeled but the model no had 355 so im guessing thats the wattage.
ill rephrase blue line, its more like blue dots lined in horizontal. length is always different since it appears and disappears randomly but mostly about half of the sreen. and its not thick mayb about the size of the basic form of line in ms office.
If you ever tried uninstalling your GPU driver and run on onboard GPU and the problem persist, we can conclude its your monitor being flawed.
If not, your GPU is having something we PC gamer called an artifact, which is essentially a defect of that said GPU's graphic processing that created an anomaly on the screen regardless whatever that is. And artifacts cannot be fixed. The cause for this are vary from a flaw product to damage caused by overclocking. You can google to confirm this, since I'm just too lazy to gives you for case examples