I believe I just bricked my captivate by flashing Congnition 2.3b6 ROM. I've already tried all methods mentioned in this forum (key combinations, usb jig...) but no way can put my phone into download mode. Now my phone has become a brick, no boot, only black screen no matter what I do to it. I think the only way to recover it is JTAG.
So I need help from someone (better in CA) who have RIFF Box (or some other JTAG devices) and have some experiences on rescue a dead Captivate. If you can help me recover it, I'm glad to pay for your help.
PM me if you can do it. Thanks a lot!