Try to upgrade my 3Gs to IOS 5 and when upgrading completed, the phone rebooted and stucked at white Apple logo.
- Unplugged the cable from PC, apple logo disappeared.
- iPhone cannot turn on with battery.
- With data cable plugged into the PC, white apple logo appeared the disappeared. (See video)
- Unplugged data cable, white apple logo disappeared instantly.
- Cannot enter DFU mode or recovery Mode.
-itune will not recognise device.
My best advice is to get it into recovery mode, as that is likely the only way iTunes will recognize it. While the phone is plugged in, try it manually a few more times. If you really find that it isn't working, try this:
Get Limera1n, click make it ra1n, it will say "entering recovery," when it prompts you to hold the home and power buttons don't do it just close Limera1n.
Your device should be in recovery mode. Open iTunes now, then click restore (not upgrade, not shift+restore). See if iTunes will then restore your device onto iOS 5 into a functional state.
**Warning** This is not an official method, I have done this for my own device at my own risk, so you do this at your own risk as well.
If Limera1n won't work because it won't even recognize your device, well let me know and I'll see what else I can think of.
Alternatively you could download latest snowbreeze from ih8sn0w.com. Open it go past credits. Then go to top left menu and select iREB. This MAY detect your phone and put it into Pwned DFU mode and iTunes MAY give you option to restore.
As with Annie's suggestion, this is only a possible of the cuff solution, could work, could make things worse. So I take no responsibility for the outcome.