DV6000 screen

Hey, I know it is a common problem, but what's happening with my laptop seems a bit puzzling.

I have a DV6383ae Pavilion, about 18 months old, after I had some troubles with the battery months ago (I used to use a double fans cooling-pad that seems to be drawing a lot of current affecting the battery) I decided to get a new one, before I did, the screen got distorted, the external monitor works great, but the screen itself shows random graphics with blue-wash all the time even on boot-up.

the puzzling thing is; when I did a recovery everything went fine, the screen worked again ... for three to four hours ... then distorted again.

My thinking is that there is something wrong with the syncing for the LCD panel, since I can see distorted graphics, but out of sync, and the question is: is it a software/firmware issue? I hope so because I don't want to pay for a new mainboard.

P.S. The laptop is out of warranty, I disassembled it before since I had to glue the screen's cracked plastic joints (no idea why the joints were broken, I do take care of the laptop and never dropped it not once, I even treat it very gently , but I think the cracks showed because of the heat ... bad plastic they use on laptops these days).

I guess HP guys don't want us to use a laptop more than one year (I am a conspiracy theorist )

any suggestions will be appreciated.
All the best.
Sam.