Hp dv6815nr White Screen? Please Help!!!

I've got a hp dv6815nr which is in the Hp Pavilion dv6700 series, The screen worked for a while until it went white with colorful vertical lines intruding the white abyss.... I've took the laptop apart twice already and reconnected every cable and cleaned out the whole laptop hoping it would be a loose cable, I even replaced the thermal compound on the heatsink hoping that was the problem but none of them work.... The screen works some times surprisingly but it goes white about 80% of the time.... I'm using this laptop as i type this with a external monitor so hopefully it's some component with the screen itself that i can easily replace because I already took this thing apart twice! The symptoms are just white screen with color vertical lines and I've reconnected every cable so that gives you a clue on what things you think I can toubleshoot... I'm hoping the inverter is gone bad because it will only take about 20 bucks and 20 minutes to fix it but I don't know how anything about inveters & laptop screens. Please give any suggestions that I can fix this problem... I've search online about this problem and it's very vague and the solutions I've seen are buying a new laptop or new screen which is 100$ which is out of the question. Please ask questions if you know how to diagnose this problem so i can find a way to fix the white screen. Thanks for your time and hopefully I can get this laptop back up and running.

link from hp http://h30434.www3.hp.com/t5/Noteb [...] td-p/77262 and this for test http://www.laptoprepair101.com/lap [...] ned-white/

if it works fine on an external monitor then it shouldnt be the graphics chip

i would suspect the ribbon cable from the base to the lcd

thats cheap enough to replace