Apple released iOS 4.0.2 for iPhone 4, 3GS and iPhone 3G to patch the PDF exploit a few days ago. It is to remind you that JailbreakMe, a new jailbreaking tool, also uses the same PDF exploit to jailbreak iPhone and iPod on iOS 4.0 and iOS 4.0.1. So if you have updated your idevice to iOS 4.0.2 and now you want to downgrade your iPhone to jailbreakable iOS, here is a complete guide.
Step 1: If you have already saved SHSH blobs for iPhond/iPod on your PC/Cydia, follow this guide otherwise leave because now you can’t downgrade.
NOTE: If iPhone 4, 3GS, iPod Touch 3G and iPod Touch 2G (MC) users do NOT have SHSH blobs saved for an older firmware, they can NOT downgrade unless Apple is signing the Firmware.
Step 2: If SHSH blobs are saved on Cydia servers, download TinyUmberall and follow the steps below to save them on PC first.
- Open the downloaded TinyUmberalla.
- Check the Advanced Options.
- Select your device, firmware and Cydia as location.
- Hit the save button to save the SHSH blobs on your PC.
Step 3: After you have saved SHSH blobs, download the required firmwares. Links are at the bottom of this post.
Step 4: Put your iPhone into a DFU Mode. Follow the steps below to enter the iPhone in a DFU Mode.
- Open iTunes and connect your phone with your PC.
- Press and hold the Home and Sleep/Wake buttons at the same time.
- Keep holding the both buttons for at least 10 sec and then release the Sleep/Wake button but keep pressed the Home button.
- Soon iTunes will show a pop up that a phone has been found in recovery mode.
Step 5: If you have got iPhone 2G or iPod Touch 2G (Non-MC), skip to step 6. For iPhone 4, 3GS and 3G, follow the steps:
- Run the TinyUmbrella
- Hit the Display SHSH button to confirm that downloaded SHSH blobs has been cached by TinyUmbrella for 4.0.1 or 4.0. (If you already have them in your PC, drag and drop the SHSH blobs in the TinyUmbrella window then hit the display SHSH blobs button to confirm).
- Then hit the Start TSS Server button.
Step 6: Now in the iTunes hold down the Shift (for Win users) / Alt (for Mac users) and click the restore button.
Step 7: Select the downloaded firmware and let the restore process begin.
iTunes will bring up error 1015, 1013 or 1011 message. Don’t worry, it’s normal. You’ve successfully downgraded your iPhone/iPod Touch firmware.
Step 8: After the successful downgrade to iOS 4.0/4.0.1, now you need to get out of recovery mode. For this purpose, click the “Kick Device Out of Recovery” button on tinyumberalla.