Downgrade Baseband Iphone 4 Possible for unlock/jailbreak?
Hello anyone back to the iphone world again I have forgotten a few things since I last hacktivated a 3g oops that slipped lol that I had a long time ago. Anyways I have an Iphone 4 on firmware 4.2.1 and a baseband of 3.10.01 and I want to unlock it with another carrier is there anyway to downgrade the baseband to the lowest possible to unlock it? As I said b4 I am a little out of the loop with the Iphone especially iphone 4!!! I know there used to be fuzzyband on cydia to downgrade the baseband, but this phone isn't even jailbroken it was an AT&T phone, so am wanting to unlock it and JB it if possible? I see there is a tool now called tiny umbrella to trick the itunes server i guess, but I don't really know how to use it or it's exact purpose? If anyone has any ideas or tips please let me know even if I have to completely restore it or whatever I don't mind I haven't even used it it's just charging now thnx for reading
- 12-27-2010, 06:10 PM #2
Fuzzyband only works on first set of 3G iphones with 5.8 bootloader. Apple since then have fix that exploit on later 3G iphones an newer devices. Thus, all newer devices since than can't downgrade their baseband.
Apple has also put in a SHSH security check in allowing / denying your ability to install a firmware. Thus, if you do not have old SHSH files saved, you can not restore to a firmware Apple does not allowed, currently they only allow 4.2.1. That's where Tinyumbrella and editing hots file to Cydia comes into play with saved SHSH files.
so when the new untethered unlock/jailbreak comes out from the dev team will I be able to avoid this problem you mentioned above with my baseband of 3.10.01 and FW 4.2.1? what should I do when it comes out to assure that won't happen when I connect with itunes and apple's server? what's the best way I'll be able to keep my unlock thnx for the response anyone else have any other opinions?
- 12-27-2010, 08:06 PM #4
You shouldn't update the phone until an JB and unlock are available that firmware and baseband. In the future, should always update using a custom firmware file to save your current and possible unlockable baseband. And, when, you connect to iTunes and it says there is a update available, just check never remind me and click on cancel. That why you don't accidentally let iTunes update your phone.
Your only option is to wait for untethered JB and unlock. In the meantime, use Tinyumbrella to save 4.2.1 SHSH files so in the future you can still restore to 4.2.1 after Apple no longer allows it.
Last edited by myzhi; 12-27-2010 at 08:08 PM.
ok thanks that's just the way the phone came I haven't owned it b4 until this week and I wanted to see how to go about unlocking and jailbreaking it since I can't do an unlock now with the baseband that I have of 3.10.01. I used to do it with a 3g that i had in 08 but now some things have changed and I forgot a few things, So let me get this straight I should run the tiny umbrella now with the baseband and FW I have to prevent any future problems with Itunes correct? Will it create a custom restore/and or FW to save for whatever reason correct? I don't even have an AT&T sim for it does it matter for any reason (for Itunes, activating it, etc) or to do with that program tiny umbrella? all I have it a tmobile micro sim as of right now. Do I need a ATT micro sim? Because I used to trick Itunes with my 3g back in the day when it wouldn't activate it with Itunes on my tmobile sim I would pop in an ATT sim real quick and take it out in itunes and wallah it would be activated. thanks for the response just don't want to mess it up when I have the chance to use it. I want to be prepared!!!!
Last edited by DrJB; 12-27-2010 at 11:08 PM.
- 12-27-2010, 11:50 PM #6
Apples send out SHSH files that tells itunes if it's OK to restore with that firmware. And, since SHSH files are unique to each iphone and firmware, you must have previously saved them to be able to trick itunes into allowing to restore to an old firmware. For example, lets say Apple release 4.3 firmware, you won't ever be able to restore / downgrade to 4.2.1 with saved 4.2.1 SHSH files. Tinyumbrella request the SHSH file from Apple through Cydia and saves them on your computer. It does not create a custom firmware. For that, you need Pwnagetool.
Is the phone current activated? If not, use official ATT micro sim, even one non active will do, and connect phone to itunes or hackivate during JB process. It's better to use official ATT sim. You can easy buy them on ebay for ~$5. Using hackivation could cause push and battery draining issue.
- 12-28-2010, 06:16 PM #9
- 12-31-2010, 08:17 AM #10
Hi there, sorry for a stupid question, i am a total noob, but basically i bought an iphone 4 a while ago, it had iOS 4.0 on it, and when 4.1 came out i updated normally through iTunes and then jailbroke it with Greenpoison. My girlfriend just bought an iPhone 4 too with iOS version 4.0, so since 4.2.1 is out i downloaded 4.1 manually and tried to install it through update (press shift) on iTunes and half way through i get an error message and it wants to restore to factory settings and then update to 4.2.1. What am i doing wrong, i have read around and i think its because iTunes doesn't sign for it anymore because of 4.2.1 being out and maybe something to do with SHSH blobs maybe, don't really get it....help anyone :P thanks in advance for any assistance
- 12-31-2010, 03:25 PM #11
Last edited by myzhi; 12-31-2010 at 03:30 PM.