Hi folks! Yesterday, I discovered that my SHSH blobs for iOS 4.2.1 are luckily available at Cydia server and I will be able to downgrade my iPhone 4 back to iOS 4.2.1 using TinyUmbrella. I restored my iPhone to iOS 4.3.5 accidentally last month. So I tried to downgrade my iPhone, at first I encountered error 3194 but after fixing, now iTunes is throwing error 1604. What do I need to do to fix iTunes error 1604? Thanks.
Asked by: Kenneth from Mechanicville, New York
Step 1: Download iREB RC4 for Windows from here
Step 2: Connect your iPhone to your PC through USB cable.
Step 3: Launch iREB and select your iPhone from the list of iOS devices.
Step 4: Then put your iPhone in DFU mode:
- Press the Home and Power button at the same time for exactly 10 seconds.
- Then release the Power button after 10 seconds but continue holding the Home button until iREB detects your iPhone in DFU mode.
Step 5: Now, iREB will start patching the iBoot of your iOS device using Limera1n exploit.
Step 6: Once done, you will see the confirmation message saying that Your device is now in Pwned DFU state.
That’s it. You can now restore your iPhone to iOS 4.2.1 without getting any error. Good luck.