a lot of the newer phones have keyboard issues. U press a key and it repeatssssssssss itsssssseeeeeeeelllllllf like so, before it flat out stops working. Not a rom issue its a hardware issue.
Sprint(thru Asurion) will send u a Brand New phone free of charge, not sure if u need the Total Protection Policy or not, I have it tho. i just activated my 4th replacement from Sprint, and all four times they've sent brand new phones. 3 of the 4 had the keyboard issue
But hey, I got enough Headphones, Hip Cases, and chargers to last a lifetime.
btw...theres a milli of these keyboard topics, just search