I've had a small crack (1/4" dia.) in the lower corner of the screen, because of this I'm told the warranty is void. My screen just went out and the phone is only 9 mo. old. I'm out 600 bucks?
The warranty will still cover the manufacturing defects. But if you have your phone repaired by a non-authorized Samsung service center, warranty will be void. You might want to check Samsung on what can they do about your problem.