the touch screen became unresponsive as you can see in this video.(sorry couldn't embed the video)

http://youtu.be/3QpNl42RO6c


apparently the phone some how detects that something is touching the screen but no action is executed at all it just does as u see in the video.

i had this problem about 4 months ago , the phone got sweat , and went into this state i put it in rice and waited for a very long time about 2 weeks for it to recover and it worked very well since then.
until the same problem came back without any water coming near the phone. i waited for a long time and no response till now.

my question is do i have to replace the screen ( i can order one and replace it myself) ? or go to nokia care and let them fix the thing and pay much higher ?

Thank you for ur time,

Ahmed