today my pre 3 was working fine, then all of a sudden the screen will not light up. The phone is on because it vibrates when I switch the phone ringer from sound to vibrate. I removed the battery and then reinstalled it. I hit the power button and the phone would give a vibration which indicates to me the phone rebooted but screen still not lighting up.

keyboard lights up
screen gives a faint blue color sometimes but most of the time just your basic black screen.
I have had phone 4 months
bought new on ebay

is this a common problem?

call att?
call hp?
warranty?

thanks for any help, thoughts, directions or a solution,

king