How to downgrade iPhone 3GS with serial number xx134 or later
0
francisvac • December 6, 2012 at 10:08am
I accidentally upgraded an iPhone 3GS manufactured after the 34th week of 2011. The iPad baseband 06.15.00 was installed and now the phone has no service. Is there a solution to restore phone functionality, or is it permanently limited to being an iPod touch?
Answers
0
iClarified • January 12, 2026 at 4:07am
The iPhone 3GS models produced after week 34 of 2011 (serial numbers starting with xx134) have a different baseband chip that can be permanently damaged if you attempt to flash the 06.15.00 iPad baseband. This often results in a No Service error or the loss of the IMEI and baseband information in the settings menu. To attempt a fix, you should use the latest version of Redsn0w. Connect your device, select Extras, then select Jailbreak, and make sure to check the box that says Downgrade from iPad baseband. This process will attempt to install the 05.13.04 baseband. If the chip was not physically damaged during the initial flash attempt, this should restore your phone functionality and allow you to use Ultrasn0w for carrier unlocking if needed.