We can downgrade the baseband for iPhone 4 under certain conditions

The baseband is definitely one of the key points of the iPhone terminals coded on a mobile network because depending on the software version of this component we can do or not decode the terminal. As you already know very well, for the iPhone 3GS you cannot downgrade the baseband and for the iPhone 3G it can only be done on terminals produced until September 2008, so a very small number of people can downgrade the baseband on old terminals. With iPhone 4, the situation is different because the device downgrades the baseband under certain conditions. More precisely, the terminal "aligns" the software version of the baseband with that of the current version of iOS available through iTunes. That is, at the moment we have iOS 4.1 in iTunes and baseband 02.10.04, but if we update to iOS 4.2 beta we update the baseband to version 03.10.01. On the old terminals, you could not downgrade the baseband in any way, but on the iPhone 4 you can do this when you restore to the current version of iOS. Taking the above example, the baseband 03.10.01 corresponding to iOS 4.2 beta 3 will be downgraded to version 02.10.04 when you restore to iOS 4.1 via iTunes.

This downgrade is ONLY possible if you have NOT modified the Windows hosts file to use the SHSHs from the Cydia server. If this change is made, then the baseband downgrade does not take place. The possibility to downgrade the baseband has existed since the launch of the iPhone 4 and there are no signs that Apple will stop it soon.

14 COMMENTS

  1. Dar daca apare oficial ios 4.2 probabil itunes nu ne va lasa sa facem restore la ios 4.1 pentru ca este o versiune noua lansata. Sau e altfel?

  2. Deci k sa inteleg mai bine, daca am un iP4 4.1; 2.10.04; pot face restore la 4.01 si sa fac downgrade la baseband?
    Am shsh salvate doar pt. 4.1, dar dupa spusele tale nu ajuta pt. ca fisierul hosts trbuie sa fie nemodificat.

  3. Toata treaba asta(dupa cum am specificat deja in articol) functioneaza doar pentru restore la firmware-ul curent care in momentul de fata este 4.1.

  4. se poate face downgrade de baseband in conditiile in care am SHSH salvat pe 1.59.00 si IOS 4.1 iar acum telefonul are IOS 4.1 cu baseband 2.10.04

  5. Am citit ce-ai scris tu mai sus insa deoarece sunt inca bulversat pun o intrebare. Ieri dupa ce inteligentul de mine am facut update la iOS 4.2 pe Iphone-ul meu 4(aveam 4.2 dar inca eram pe modul locked telefonul fiind cumparat din state si asteptam cu nerabdare 4.2-ul, cei de la DevTeam afirmand ca dupa aparitia acestui upgrade va aparea si unlock-ul pt 2.10.04)…acum m-am ales cu 03.10.01 si telefonul blocat de tot la faza cu “insert a valid sim tu unlock your phone” okey am reusit intr-un final dupa ce am adaugat in acel fisier hosts un ip` sa-i fac downgrade la 4.1 dar mi-a ramas baseband-ul. Pe un forum strain mi-a raspuns un tip si mi-a zis ca o sa raman luni de zile poate si un an cu telefonul pe post ipod deoarece cinee stie cand o sa apara unlock pt noul baseband. Intrebarea mea e..poot face ceva toootusi ?(am citit caa in general NU se poate face downgrade de baseband)

  6. Din cate stiu eu nu se mai poate salva SHSH pentru 4.1. Daca nu se mai poate salva SHHS nu se mai poate face nici restore. Ideea cu downgrade-ul de baseband era ca puteai reveni de la 03.x la 02.x facand restore din iTunes dar cum 4.1 nu mai merge asa atunci nu prea ai ce face.

  7. salut am si eu un iphone 4 cu ios 4.1 si baseband de 2.10.04, as putea sa ii fac un downgrade de ios la 4.0? si daca ii fac se face automat si downgrade de baseband la 1.59? astept un raspun