yeah, about a month ago i had a problem where it won't start up. it just go onn and then off. it stops at the samsung welcome screen. so i brought it to a local repair shop and they did something and it was working again. they said that they dont know what it was. but today, i was texting and suddenly the screen starts to flicker and after a while it just became black. i pulled the battery out and in again but its still black. help me please.