My son Jail broke his phone in December of this year and it worked fine until about 2 weeks ago. He used Pangu 8.1.1 and hasnt added a jailbroken app for over a month. 2 weeks ago he showed me his phone was stuck on the apple logo flashing on and off. I read on this forum and tried to hold down the power button and round circle button to attempt a hard reset but nothing, Tried the volume trick nothing. Tried to restore the phone and get an error 21. Now the phone wont power on unless it is connected to the charger or the computer and itpops up to the itunes screen even when its in the regular power outlet on the wall. Had a friend try to restore it with his mac that didnt work and change the battery and neither of those worked either. Any ideas???