It is sad that iPhone 4 baseband 4.11.08 / 4.12.01 owners have not found a reliable solution for a permanent factory unlock. The desired baseband to downgrade to is 01.59.00.
Since SAM unlock, Gevey, R-SIM, and Rebel Micro Pro can not unlock the baseband, it is similar to iPod Touch in functionality. We are still waiting for a genuine solution that will last forever.
Whoever says he has software unlock for 4.11.08 is not telling you the truth! We have news for those who have totally lost hope and thinking of getting another iPhone which is factory unlocked. There is a hardware hack which can downgrade 4.11.08 to 01.59.00 baseband and hence, you can use the latest version of ultrasn0w after the downgrade.
|Infineon X 618 Baseband Chip|
The method is provided by beijingiphonerepair and requires you to open up the iPhone, take out your logic board and sent it to them. The method is dependent upon chip replacement service.
The downgrading of iPhone 4 baseband 4.11.08 / 4.12.01 requires these components:
- Intel 36MY1EF 128MB NOR chip which costs US$67.00.
- Infineon Baseband Chip X618 (pre-programmed) baseband 1.59.00 which costs US$88.00.
- Worldwide standard shipping (can be tracked online and will take up to 20 days) which is free.
- China domestic first class express shipping which is free
- Labor charge which costs $24.00.
- 30-days warranty.
This is going to work but the main issue the workers at beijingiphonerepair face is sourcing those rare 1.59.00 baseband chips.
Downgrade iPhone 4 Baseband Warnings
- Only custom-made firmware should be used for upgrading while iTunes should be strictly avoided
- The IMEI serial number change will be caused by the change of the chip so the unlocked iPhone can be activated using any hacktivated custom firmware and latest ultrasn0w.
- There will be no issue in the process of restoration to stock firmware.
We know the method is hectic. But this hardware hack to downgrade iPhone 4 baseband 4.12.01 / 4.11.08 to 01.59.00 is reliable and can allow you to unlock iPhone using ultrasn0w.
Please feel free to share your thoughts!