i am using a Dell Inspiron 15 R N5010 (H66P7BS).


after using the laptop for  about 5 to 10 mins the laptop just freezes and a weird screen shown up after which i had to force shut down .

later when i restart the laptop it takes several minutes for the screen to show up.

i need to leave the laptop on for a while and the screen turns on only after the laptop overheats. this procedure often extends upto about 20 to 30 mins.

its usually a black screen or a white screen with black stripes all along.

now-a-days i am also experiencing a screen showing various color dots and also a screen of color dots consisting of several text elements mainly involving symbols like "[" and letter "$".

i also learnt that this problem might be caused by a faulty RAM as mentioned in several websites, but there were no issues with the RAM as checked by the windows. ( if have also included a screen capture showing the scan status )

the link of the document showing several captured images of the frozen screen
: - 
https://drive.google.com/file/d/0B-1P-z8E9HWmTGdEa1NWRTFOOUE/edit?usp=sharing

could anyone help me get out of this problem or suggest a reason why i am experiencing this situation.

Thank you.