17 R4, keyboard keys not working

Hello

I have an alienware 17r4 that I bought from Best buy.  About a month ago the F4 comma and delete keys stopped working.  They would start working again every now and then but now has completely stopped.  I tried reseating the KB cable but that didn't seem to help.  I tried an external keyboard and it works fine.  

I searched google for this issue and it seems like there are many occurrences of this happening where random keys would stop working.  Has there been a solution to this other than replacing the keyboard?  I believe my laptop is already out of warranty.