Recently my SGH-1897 stopped booting. It would go to the clockwork mod screen. From there, I tried to flash a new rom, but it never worked. First it told me I had the wrong rom for the phone I was using, so I downloaded a different one that said it would work for 1897, but it would fail during the flash. Now, it won't boot at all. It goes to the 'at&t World Phone' screen and stays there. I've tried Vol +, Vol- and Power together, but no change. Help?