Hi guys, I have this red horizontal lines problem instead of black. I try to connect my macbook to an external display using HDMI to check whether my VGA is okay or not. It turns out that the display is okay on external display, no red at all. Does it mean that both of my VGA is okay? Or maybe one of them is not okay? Oh and two vga of my macbook pro 15" are intel hd and amd radeon hd Thanks.