Help on Baseband/JBing :(

[newguy1]

Sorry if its a repost... Guyz..I am totally new to JBing (new to this site as well )....but this baseband issue is really confusing me and scaring me from JBing my iphone 4. I have few queries. IF you experts can help me out..really appreciate it

1> I have an iphone4 its a Factory Unlocked phone. (i am assuming it so, coz I bought it as a factory unlocked, and I have updated it multiple times via Itunes, I even three diff. sims into the phone it worked fine), Also, there is no sign of any Cydia or JB related stuff inside the phone. IS there anything else to confirm its a FU phone?? Model: MC603HN

2> Now I was looking for JBing tools and help all over the net and found this site helpful, but as I mentioned I have no idea about wat and how a baseband effects my phone by updating via itunes or JBing..some queries on BAseband:

a> What is it exactly?
b> How does it change (as in how does it update to some version, 4.Xx.xx or watever etc etc.. is it through each OS /Delta update from Apple ? )
c> Each and every phone is having a diff. baseband (as per info on the net, wat does tat mean?)
d> So if my Iphone is FU and if JB using say redsn0w, will my baseband update ?
d.1> - if my baseband updates on JBing , does it update to some dev. made firmware update or an official apple update?
d.2> - After update and JBing, say in the future if I want to come back to stock OS, and I happen to update via ITUNES (losing JB), will my baseband change back to the apple's baseband or will it fail and if it fails, wat will happen to my phone?
e> I have been advised by many to PRESERVE BASEBAND using redSnOw and go ahead. So wat will be the case for d.2> (above query) now??

btw my baseband now is: 4 12 1

3> Right now I have upgraded to 5.1. So I see there are no untethered JBs for 5.1 yet. So if I wan to go back to 5.0.1 and try. is it possible?

Please bear with me and try to answer my queries. As I am the guy who likes to keep the Stock features of the phone intact at the same time try to fiddle with other options like JBing. Too much greed :/

thanks in advance for ur patience guyz...

 

[iDonev]

1> Don't worry. It sounds like an official unlock.
a&b> JB does not affect BB. The only thing that affects BB is updating firmware via OTA/iTunes.
c> Each firmware has a unique BB for all supported devices. Example: two iPhone 4s updates officially to the same firmware will have the baseband.
d.1> The BB is unaffected by JB.
d.2> Since you have an official unlock, you should concern yourself with basebands - you'll be able to use any SIM no matter what you do.
e> Baseband preservation is for people who manually unlock their devices after each firmware update.
3> Open Cydia and let the home screen load. On the very top you will see all firmwares you can restore to. If you don't see them, you will only have access to the current one.

 

[newguy1]

1> Don't worry. It sounds like an official unlock.
a&b> JB does not affect BB. The only thing that affects BB is updating firmware via OTA/iTunes.
c> Each firmware has a unique BB for all supported devices. Example: two iPhone 4s updates officially to the same firmware will have the baseband.
d.1> The BB is unaffected by JB.
d.2> Since you have an official unlock, you should concern yourself with basebands - you'll be able to use any SIM no matter what you do.
e> Baseband preservation is for people who manually unlock their devices after each firmware update.
3> Open Cydia and let the home screen load. On the very top you will see all firmwares you can restore to. If you don't see them, you will only have access to the current one.

Thanks a lot iDonev, for patiently answering the queries.
in d.2> did u mean "you should NOT concern yourself with basebands?"

Just out of curiosity, (though my phone is FU) say I preserve the baseband using redsn0w, does the following hold true:?
-- I will be able to update to stock BB whenever I update to a new Stock OS from itunes (removing the JB), hence my phone as good as new!

IF a phone is not FU, and by mistake if some1 updates to some BB, and it does not work, is it possible for them to rectify or the phone will be just bricked? (this is for a non FU iphone with my friend)

Thanks in advance

 

[iDonev]

Thanks a lot iDonev, for patiently answering the queries.
in d.2> did u mean "you should NOT concern yourself with basebands?"

Just out of curiosity, (though my phone is FU) say I preserve the baseband using redsn0w, does the following hold true:?
-- I will be able to update to stock BB whenever I update to a new Stock OS from itunes (removing the JB), hence my phone as good as new!

IF a phone is not FU, and by mistake if some1 updates to some BB, and it does not work, is it possible for them to rectify or the phone will be just bricked? (this is for a non FU iphone with my friend)

Thanks in advance

Yes, I meant to say you should not

OK, first off all basebands are stock. The only exception is that you can run iPad basebands on iPhone 3G/3GS.
Let's say you have baseband 1 and you are running on firmware 1; when firmware 2 comes out, your baseband will be updated to baseband 2. When you update using redsn0w you get to firmware 2 while keeping baseband 1.

Lastly, the baseband only affects your ability to unlock the phone. Even if you have a carrier locked phone and update your baseband, you'll still be able to use the device as an iPod touch. You can't brick a device by updating your baseband.