Alright, I joined this forum just so I can reply to this old thread. For the past two days I've read threads like this teaching how to get the iphone running again when it's stuck in the boot logo or boot logo cycle.
Here was my situtaion:
My internet connection was net detecting my modem, my intensions were to SSH some files on my phone. So I didn't want to wait all day for the phone to connect on its own so I decided to reset all network settings in the general settings area. My phone went to the black screen with the white apple logo and it was stuck there. I saw it flash once, twice..and I thought to my self it doesn't normally take this long so I held the power and home button to reboot. nothing.
And my search began on how to fix my phone. I have a 3GS old bootrom on 3.1.2 by the way. I read numerous posts on SSH, iRecovery, iPhonebrowser, and reseting. Resetting was my very last option.
I tried SSH but my wifi was not working to begin with so this didn't work. You phone has about 5-10 mins time limit when rebooting, and during this time you are able to SSH or connect to it in other ways before it reboots again. So SSHing didn't work.
I downloaded iPhonebrowser, iFunBox, iDisk(?) and other USB form of browsing the iPhone files, but since iTunes can't detect the phone unless I put it in DFU or Recovery, these programs will also not work. They couldn't detect the phone even when I tried reconnecting the plug.
Next I went to iRecovery. It recognized the phone but entering "printenv", "setevn auto-boot true"...the terminal has nothing in responce (others in the thread I was reading did say theirs responded back saying it completed the task but mine just when to a new line). I tried this about 8-10 times because some said it works after doing it so many times.
Next?..I blackra1ned again to force the start, nothing. After several hard reboots I tried redsnow?and nothing.
Last I read where that when your phone reboots and it doesn?t complete the task it starts to recover it self so forcing hard reboots by holding the power and home button only corrupts the phone memory even more. So here is what I did?
I turned off the phone completely no usb plugged in (Hold the home and power button until it turns off). Made sure if was off by tapping the home button, and the screen stayed off so next I turned it on and I waited about 3-5 seconds before I plugged the phone into my usb wall charger and I left it there. After about 4 hourse I heard a vibrating sound and at first I thought it was a truck outside. One minute later, bzzzz, buzzzz, bzzzz, buzzzz, bzzzz, buzzzz. I realized it was my phone and all the buzzing was it receiving all the messages I missed.
No Restoring needed. No DFU. No Recovery mode. Just Turn the phone off and plug it in the wall charger so that it has enough battery life. Mine took about 4 hours, but this process all depends on how badly your phone was corrupted.
One last note, I have about 40 apps?and I did install categories from cydia to speed up the reboot process, because if springboard takes longer than 5 mins to boot your apps, you phone will never boot (this is according to what I?ve read). Sorry Long post but I thought you need to know where or what my phone status was when I got it to work.