Recovery Mode

• Depending on the type of jailbreak method you use for your iPhone, you may be required to put the device in recovery mode. When the iPhone is in recovery mode, an iTunes logo and USB cable are displayed on the screen and you are unable to access your phone’s normal functions. A failed jailbreak can cause the iPhone to fail to come out of recovery mode as it should when the jailbreaking process is complete. If your iPhone is stuck in recovery mode you can typically resolve the issue by connecting your iPhone to the computer.
  
  

Jailbreak Software

• There are several different jailbreaking methods, ranging from those that are browser-based such as Jailbreakme.com and those that require connection to the computer, such as QuickPWN, blackra1n and Spirit. Users who use the incorrect jailbreak software for their iPhone may find that the device is stuck as a result of trying the jailbreak with that particular software. IPhone users can usually check the compatibility of the jailbreak software by looking at the iPhone requirements for the jailbreak program and comparing those to the current version of their iPhone.
  
  

Firmware Incompatible

• Although jailbreaking is not illegal, Apple does not support the practice of jailbreaking the iPhone. As a result, each new update to the iPhone’s firmware patches up previous vulnerabilities that made jailbreaking the device possible. IPhone users who have an iPhone that is stuck after trying jailbreaking may find that the iPhone is stuck because the firmware was incompatible to begin with. You can avoid this issue by checking that the firmware is compatible; if you didn't check and installed incompatible firmware, you can almost always resolve this problem by simply restoring the iPhone to the factory default settings through iTunes.
  
  

Reset

• In many cases, the iPhone may be stuck after trying a jailbreak because it needs to be reset to complete the process. Resetting the iPhone can fix most other issues with the device locking up because it forces all applications, including those that are causing the problem, to close. Performing a normal reset by holding down the “Power” button until the screen goes black will generally resolve freezing, although you may need to perform a hard reset by holding down the “Power” and “Home” buttons until the screen goes black.