I have a Dell Inspiron 8600 laptop which display stopped working all of the sudden. It started to show a purple fog pattern along with some color vertical lines. I talked to Dell support and they told me that is a screen gone bad and I should get a new one which I did. But surprisingly the new display won't work either! The pattern on the screen is different but still no picture. So I tried to connect the old display to another laptop (Lenovo Z61) and it turns out it works just fine with it! So please help me to identify the cause of the issue. I think it could be a video card but the external display works flawlessly. I appreciate your thoughts about it so I won't need to buy spares which I don't need.
P.S. Please do not suggest to contact Dell support again.