Stuck in apple logo, but something extra.

So here's the thing, i was in ipsw 4.2.1 in my iphone 3G, and i've read that if i want to be able to unlock it with ultrasn0w i'll need baseband 6.15, since i was having 5.15. So i followed the tutorials from the website and everything went perfect but when rebooted the iphone got stucked into the apple logo. The interesting part here is that i'm not able to put the phone into DFU mode manually, this is because my Hold button it's broken, so i did all the things above with the WTF Mode, but now, i can't even get the phone to be recognized by the PC, so not even far to get it in to a restauration mode, i've tried unplugging the batterie, connecting it again and connecting to the usb cable, and when it turns on, hold the home button, but nothing. What can i do? Regards.