Uploaded January 2014 | Updated September 2026, 9 minutes 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 downgrading my iPhone 3GS (MC Model, new bootrom) iPad 6.15.00 baseband back to 5.13.04 naturally flashed by an iTunes iDevice update/restore from iOS 3.x.x to iOS 4.0, 4.0.1, 4.0.2. Downgrade an iPhone 3G or 3GS iPad 6.15.00 baseband to an older one like 5.13.04 has a lot of advantages. First, it removes all issues or bugs of 6.15.00 installation. So, iPhone restore from iTunes don't need a custom firmware and GPS and mobile network are working as they should. Secondly, 5.13.04 baseband is unlockable with UltraSn0w.
If your iPhone 3G or 3GS is unlocked with iPad 6.15.00 baseband, you should downgrade back to 5.13.04 and unlock it again with UltraSn0w. Your iPhone will be more stable and also more reliable.
Please read carefully instructions provided by RedSn0w, your iPhone may not be elligible to 06.15.00 update or 5.13.04 downgrade. See the most important at 02:34 .
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 downgrading my iPhone 3GS (MC Model, new bootrom) iPad 6.15.00 baseband back to 5.13.04 naturally flashed by an iTunes iDevice update/restore from iOS 3.x.x to iOS 4.0, 4.0.1, 4.0.2. Downgrade an iPhone 3G or 3GS iPad 6.15.00 baseband to an older one like 5.13.04 has a lot of advantages. First, it removes all issues or bugs of 6.15.00 installation. So, iPhone restore from iTunes don't need a custom firmware and GPS and mobile network are working as they should. Secondly, 5.13.04 baseband is unlockable with UltraSn0w.
If your iPhone 3G or 3GS is unlocked with iPad 6.15.00 baseband, you should downgrade back to 5.13.04 and unlock it again with UltraSn0w. Your iPhone will be more stable and also more reliable.
Please read carefully instructions provided by RedSn0w, your iPhone may not be elligible to 06.15.00 update or 5.13.04 downgrade. See the most important at 02:34 .
