I am getting White Horizontal line on top of the screen.
I plugged out signal cable, those white horizontal line is gone. but I plug in switch cable, horizontal line appearing on top of the screen, so what's causing this?
I see GeForce 210 but no GTX 210 when I searched in Google. Anyway, what connection are you using? I haven't seen it mentioned yet. If you're using DVI, try VGA or DP. To be thorough, have you tried connecting the monitor to another computer?