This is a general guide for those who are new to jailbreak arena. The stock IPSW file is the one which is unmodified and is directly downloaded from Apple website. Custom IPSW is the firmware file made by using tools like Sn0wbreeze or PwnageTool. Restoring custom IPSW to your iPhone not only jailbreaks it but also helps you to preserve your current baseband for unlocking purpose.
When you try to restore stock iOS file to your iPhone, iPod Touch or iPad, the bootloader of your iDevice accepts it without throwing any error. The iBoot of all new-bootrom iDevices is well capable of differentiating between stock and custom IPSWs. So, if you will try to restore custom IPSW, it can throw error 1600, 1601, 1602, 1603, 1604, 21, 3194, 3014 or 1013.
Fix iTunes Error 21:
iTunes error 21 means you are trying to restore the custom IPSW through Recovery Mode instead of restoring through DFU mode. To put your iDevice in DFU mode, hold down the Home+Power button for 10 seconds. After 10 seconds, release the Power button but keep holding the Home button until iTunes detect your iDevice in DFU mode.
Bypass All iTunes 16xx Errors:
- Download iREB for Windows from here. Mac OS X users should follow this guide.
- Connect your iDevice to your PC via USB cable and close all instances of iTunes.
- Launch iREB, choose your iDevice from the list and use the following instructions to put your iDevice in DFU mode:
- Hold down the Home+Power button exactly for 10 seconds.
- After 10 seconds, release the Power button but keep holding Home button until iREB detects your iPhone in DFU mode.
Fix iTunes Error 3194:
iTunes error 3194 means you are trying to downgrade your firmware and iTunes failed to get SHSH blobs from Apple server. If you have already saved your SHSH blobs on Saurik server, you can use TinyUmbrella to get your SHSH blobs from Cydia. Use the instructions below to get SHSH blobs by redirecting iTunes to Cydia server:
- Download TinyUmbrella for Windows or Mac OS X from here
- Connect your iDevice to your PC or Mac via USB cable.
- Launch TinyUmbrella and click on Save SHSH button. Wait while TinyUmbrella downloads your SHSH blobs from Cydia server to your hard-disk drive.
- Once saved, switch to the LOG tab and click on Start TSS Server button. Make sure iTunes is closed at this time.
- If you see the following two lines at the end of your LOG, it means TSS server has started successfully.
TSS Server Started!
TSS Accepting connections...
Fix iTunes Error 3014:
iTunes error 3014 means your Windows or Mac HOSTS file is not correctly edited and have some error. Just remove all instances of 18.104.22.168 gs.apple.com or 127.0.0.1 gs.apple.com from HOSTS file and you are good to go.
On Windows, your HOSTS file should look like this:
On Mac, your HOSTS file should look like this:
Steps to Restore Custom IPSW Using iTunes:
If you are downgrading firmware, make sure TinyUmbrella TSS Server is running. If you are upgrading to the latest version or you are iPhone 3G or iPod Touch 2G (MB) user, skip this step. Put your iPhone, iPod Touch or iPad in Pwned DFU Mode and follow the steps below to restore custom IPSW:
- Open iTunes on your PC or Mac
- Click on your device name from the side-panel to view the summary page.
- You will see two buttons on the summary-panel i-e Check for Update and Restore. Hold down the SHIFT key (Alt (Option) for Mac) and click on the Restore button.
- Browse to your desktop and select the custom IPSW which you want to restore.
- Now sit back and relax while iTunes restores the custom IPSW on your iDevice (hopefully with no more iTunes error). Once restored, your iDevice will reboot automatically.
- Download RecBoot to Fix iTunes 1015 Restore Error
- Download RecBoot v1.3 for Windows, Mac OS X & Linux