iOS users have to deal with DFU mode, recovery mode and iOS stuck every now and then - there is even a redsn0w WTF mode. Maybe you need to put iDevice in recovery mode because you can’t update or restore iPhone, iPad or iPod, use recovery mode to fix Apple logo screen stuck, force iPhone to restart in case of DFU mode stuck/black screen of death, etc.

Tenorshare ReiBoot is a wonderful solution to all these problems, making it possible to induce the recovery mode and DFU mode, as well as exit either in an effortless manner, in a one-click operation. If your device is already in recovery mode or DFU mode, ReiBoot will identify it accordingly, allowing you get out of both modes with the same easy one click operation.

While trying to fix an Apple iPhone 3G stuck at boot logo because of a corrupt baseband, I frequently encountered "iPhone 3G (WTF Mode)" error in redsn0w never seen before (as shown below). The older redsn0w version which worked well with this old hardware (Apple iPhone 3G) showed no solution to the problem but thankfully the newer one pointed at the right direction.

With all the IPSW firmware versions, various Apple devices and a variety of tools for jailbreaking the whole process becomes very confusing. While working with custom firmwares and jailbreaking one must follow the correct sequence of steps with right tools and software versions, otherwise iTunes throws an error and the device gets locked down in a restore or DFU loop.

One such often encountered error while restoring an custom IPSW file using iTunes is - "An unknown error occurred (Error 1600)." as shown below.

Apple blocks users from restoring older iOS firmware's, while this is a good security feature and a method to avoid OS fragmentation. This also prevents users from using jailbroken and carrier-unlockable software versions.

This practice makes iOS upgrade difficult for users relying on software unlock like ultrasn0w which is supported on older basebands only, If you are trying to upgrade an Apple device to an non-supported iOS version even when using TinyUmbrella - the iTunes restore process may throw up error 3194 and 1600 as shown below.

Here are solutions to get past these errors and flash custom, snowbreezed IPSW files to your Apple iPhone, iPad and iPod's.