How to fix boot loop on jailbroken iPhone or iPad via 'No Substrate Mode'

Guide to fix boot loop issues on jailbroken iPhone or iPad using No Substrate Mode.

Avid iOS jailbreakers can now avert the frustration of trying to reboot a jailbroken device that's stuck on endless boot loop mode, thanks to Cydia founder Saurik's ingenious ways of fixing the buggy jailbreak tweak via No Substrate Mode.

Basically, you need to boot your affected iPhone or iPad into No Substrate Mode which enables you to uninstall the faulty or incompatible tweak without losing your precious jailbreak.

The No Substrate Mode method of uninstalling the jailbreak tweak is safer than a complete restore on iTunes as the latter will completely wipe out your precious user data including the installed jailbreak apps.

Whenever you are stuck at the Apple logo, you could avoid firmware restore at all costs as Apple has stopped signing older firmware while also patching up existing exploits in newer firmware and this could prevent you from rejailbreaking your device.

Here is how to fix a boot loop issue using No Substrate Mode:

  • Press and hold Power and Home buttons together for 10 seconds until the device shuts down and reboots.
  • Allow the device to boot into the Apple logo screen. Now press and hold the Volume Up button until you see the Lock screen.
  • You will now have restricted access to the Cydia apps wherein none of the Substrate-based jailbreak tweaks are operational and you can only uninstall the faulty app. Note: Some app settings could be inaccessible via the Settings app.
  • Nevertheless, just launch the Cydia app and navigate to the tweak you want to uninstall and remove it from the device.
  • Once you get rid of the faulty jailbreak app, you can safely reboot your device and the boot loop issue should be fixed.

[Source: iDownloadBlog]