Geohot released Purplera1n to jailbreak iPhone 3GS but this small tool supports OS 3.0 at the moment. So who updated their iPhone to OS 3.1 beta and now wants to downgrade back to OS 3.0 need to put their iPhone 3GS in DFU mode to downgrade to OS 3.0 But when you downgrades you iPhone you will be encountered with error 1015. Usually we use iRecovery to put iPhone back to normal mode. iRecovery is a libusb-based command line utility for Mac OS X and Linux (perhaps Windows too). It is able to talk to the iBoot/iBSS in Apple’s iPhone/iPod touch via USB. iRecovery is a command line based tool and if you haven’t used it before we don’t recommend you. As an alternative we can use Purplera1n to put our phone out of error 1015 here is a simple how to on downgrading OS 3.1 to 3.0 on iPhone 3GS.
- iTunes 8.2 installed on your computer (you can download it here)
- Firmware 3.0 Original iPhone 3GS (you can download it here)
1st Connect your iPhone to your computer via the USB cable. Switch off the device and put it in DFU. To do this: Click the Home + Power On button for 10 seconds exactly, then release the power button and continue to click on Home.
3rd A new pop-up that asks you a confirmation before performing the restore. In this case, you must confirm by clicking “Restore”:
4th The second a quick procedure that will extract the software, verify the information on the Apple site and prepare the riprisitno. After a few minutes finally begin to restore itself and towards the end of the process will get an error from iTunes. (Do not worry, everything is normal).
5th In fact, the 3.0 firmware has been properly loaded on your device, but the error 1015 will appear on the screen icon in iTunes with the USB cable, which affects the use of the phone. To put your iPhone out of error 1015 you can use iRecovery or Purplera1n but we recommend you to use Jailbreak with Purplera1n because it’s easy and simple. Now jailbreak your iPhone with purplera1n RC2 and your device will reboot in FW 3.0. For Jailbreaking your iPhone 3GS with Purplera1n follow our Guide to Jailbreak your iPhone 3GS with Purplera1n