when it is stuck at the boot logo, I just hold down the home key and power key at the same time. Try it again. Once you get into the stock recovery do a factory reset. That is what you need to aim for.
I had the same problem with my phone. I couldn't get the exclamation screen to come up by holding power and home.I started button mashing out if frustration and it popped up. I got it to factory reset and the phone loaded up but the home button volume up button and the power butto. Were the only ones that worked. I tried to restart the phone again and there waited the damn m logo. I button mashed again, and now the battery icon came up after about 20 resets. Not sure what I'll try next if my genius button mashing tactic didn't work.