I have a Asus gamer of republic laptop G75V. And the screen has a red line going vertical and it shows up on every color but white. I have already plug it into anouther screen to make sure it not a graphic issue and I don't think it a wirer issue because when I move the screen back and forth the line does not disaper. Could this be a screen issue?
It's a display problem and you need to contact the manufacturer to have them repair or replace the screen. But before you contact them try to uninstall and reinstall the graphics card driver as well because they will surely ask first if you have done some troubleshooting steps already. Also to make sure that it's a screen problem boot the laptop into BIOS and if you'll have that red line on it you're sure that it's the display.