It wasn't a good day at all with all day raining outside. I have an iPhone 4 with iOS 5 upgraded from 4.3.5 yesterday. I tried to jailbreak and with redsn0w it was successful. I also tried to download a custom boot logo. After installing boot logo, Cydia attempted a restart. That was just where it started. The phone was not connected to the computer. It tried to reboot but stuck at apple logo. I remembered to boot it up from computer, so I quickly shut down the phone and tried to get into DFU state. While I was holding power and home buttons, apple logo appeared about 2-3 seconds and vanished, but about 1 second later it appeared again and vanished in 1 second. That meant to be a failure. Tried a few more times but the result was the same. At last, none of the buttons affected the phone. The phone isn't on DFU state, neither iTunes nor redsn0w/iReb/etc. can not detect the device. It doesn't power up or show any response to any action. Now I'm waiting for the battery to be drained (actually I'm hopeless) It happened when trying to update to jailbroken 4.3.5 from jailbroken 4.3.2, but at that time I was able to recover the device after 16 hours of effort. But at that time, device responded the buttons unlike this last situation. Any idea?