We will mention some common errors that some of Jailbreak users stuck on when the jailbreak process failed (Jailbreak failure) and we will try to give you some sort of steps to fix these errors & cases :
Case 1 :
You got Black Screen.
Case 2 :
Your iDevice Suck on Apple or Pineapple logo.
Your iTunes giving Error 21,2005 or 3194
Case 4 :
Stuck in connecting to your iTunes.
How to fix these errors ?
1. try to reinstall iTunes or you can change your computer to use another installed version from iTunes.
2. put your iDevice in DFU mode, follow the below step to do go to DFU mode:
* Backup your data.
* Hold “Home Button” and Power Button for 10 seconds.
* Release “Power button” while keep holding the “Home Button” for another 10 seconds.
* While holding the home button, connect your iDevice with your PC using USB Cable.
* Recovery mode will be detected by the iTunes.
* click on the restore button to restore your iDevice. (this will delete all data on your iDevice and will restore your iDevice to latest firmware)