It has become complicated to unlock your iPhone device. One of the proof is the release of Ultra Snow 1.2 for iPhone 3G and 3GS on iOS 4.2.1, 4.1, and 4.0.2 that also needs to update your baseband to 06.15.00 before you can use this unlock tool. Now we have another problem with it. Many unlockers have reported that updating to baseband 06.15.00 may cause GPS to not function properly.
Although some users are not facing this problem but few are experiencing this issue. It has been confirmed by the iPhone Dev Team.
Unlockers have been reporting mixed results about GPS functionality at 06.15.00. Until we can track down what differentiates those who retain GPS vs. those who lose it, be conservative and assume youíll lose GPS at 06.15.00. As we work on finding the cause (and possibly a fix), please report your personal findings in our comments section. (Update: early indications are that while 06.15.00 is capable of GPS, it will require some further hacks. But please still be conservative and assume you will lose GPS at 06.15, in case the hacks donít work).
ThreeFlight2005 which is a hardware designer tells why this problem is occurring:
The iPad uses the same, Infineon X-GOLD 608 PMB8878, baseband chip as the 3G and 3GS. (The iPhone 4 uses the Infineon X-Gold 618 PMB9800 Baseband chip) This is the major reason that substituting the iPad Baseband has allowed an unlock. The iPad Baseband is compatible with the PMB8878 Baseband chip; however, it probably does not contain the corret Memory Map and Read-Write commands to interface with the old PMB2525 GPS Chip.
The iPhone Dev Team is currently working to fix this issue. Many people are not facing this issue after updating their baseband to unlock their devices.
You might also like to see:
- Update iPhone 3G,3GS Baseband To 06.15.00 & Unlock On iOS 4.2.1 Using Ultra Sn0w 1.2
- Ultra Sn0w 1.2 Unlock For iPhone 3G / 3GS On iOS 4.2 / 4.2.1
- Redsn0w 0.9.6b5 Jailbreak On iOS 4.2.1 To Update iPhone 3G/3GS Baseband To 06.15.00