Default VS980 'Knock On' Fix?

After hours of searching i havent found a definitive answer. A couple days ago knock on quite working, and i have got a spots on the upper part of the screen that arent very responsive, sometime not responsive at all, in certain apps. From what I gather this is a common issue and hardware related. Is there a fix for this? Is it matter of replacing the digitizer/ lcd combo? Is a loose connection issue? I can get a insurance replacement, but i really don't want a reman unit. LG wants the phone for 5-7 days to determine if if unwarrantable or not. Anybody have any for sure information on this? I am stock kitkat unrooted.