Uploaded January 2014 | Updated September 2026, 3 hours ago
WARNING: BASEBAND LEVEL MODIFICATIONS
Before doing anything, you need to understand that if something goes wrong by modifying something at baseband level of an iPhone, some functions related to phone, mobile network, Wi-Fi, Bluetooth, every things that require an antenna could be bricked definitively. There is sometimes no way to restore.
I AM NOT RESPONSIBLE OF WHAT MIGHT HAPPEN TO YOUR IPHONE BY FOLLOWING THIS TUTORIAL.
In this video, I'm updating my iPhone 3GS (MC Model, new bootrom) baseband to iPad's 06.15.00 to downgrade it back to 05.13.04 ( youtube.com/watch?v=7ZczdJoBCCo ) for unlock & iOS downgrades. The iPad 06.15.00 baseband was used to unlock with UltraSn0w iPhones 3G & 3GS which had an unsupported baseband version. Installing it bring some issues to the iPhone, like buggy GPS & phone network, phone can only be restored with a baseband preserving custom iOS firmware because baseband can't be rolled back (06.15.00 is higher than the lastest iPhone 3GS official baseband). A 06.15.00 baseband downgrade function has been added to RedSn0w jailbreaking utility to downgrade it back to 05.13.04 which is official, stable and unlockable with UltraSn0w.
Please read carrefuly instructions provided by RedSn0w, your iPhone may not be elligible to 06.15.00 update. See the most important at 03:14 .
WARNING: BASEBAND LEVEL MODIFICATIONS
Before doing anything, you need to understand that if something goes wrong by modifying something at baseband level of an iPhone, some functions related to phone, mobile network, Wi-Fi, Bluetooth, every things that require an antenna could be bricked definitively. There is sometimes no way to restore.
I AM NOT RESPONSIBLE OF WHAT MIGHT HAPPEN TO YOUR IPHONE BY FOLLOWING THIS TUTORIAL.
In this video, I'm updating my iPhone 3GS (MC Model, new bootrom) baseband to iPad's 06.15.00 to downgrade it back to 05.13.04 ( youtube.com/watch?v=7ZczdJoBCCo ) for unlock & iOS downgrades. The iPad 06.15.00 baseband was used to unlock with UltraSn0w iPhones 3G & 3GS which had an unsupported baseband version. Installing it bring some issues to the iPhone, like buggy GPS & phone network, phone can only be restored with a baseband preserving custom iOS firmware because baseband can't be rolled back (06.15.00 is higher than the lastest iPhone 3GS official baseband). A 06.15.00 baseband downgrade function has been added to RedSn0w jailbreaking utility to downgrade it back to 05.13.04 which is official, stable and unlockable with UltraSn0w.
Please read carrefuly instructions provided by RedSn0w, your iPhone may not be elligible to 06.15.00 update. See the most important at 03:14 .
