1. sandos's Avatar
    In case anyone needs to, there is now a way to downgrade the 3GS back to 3.0 so that you can re-jailbreak your device.

    Important points here are this... You must have your ECID SHSH on Cydia's server. You would remember this because it would have said "This iPhone 3G[S] has an ECID SHSH on file" at the top of Cydia when you opened it. Also this method will not downgrade your baseband to the one needed for the soft unlock. Once a baseband is updated on the 3G[S] it cannot currently be downgraded.

    This is important because it seems that in order to apply the Jailbreak to 3.1 on the 3G[S], you will need to have a phone that is already jailbroken, thus the need to go back to 3.0 and re-jailbreak using redsn0w or purplera1n.

    For the how to go to saurik's guide at Caching Apple's Signature Server - Jay Freeman (saurik).
    Last edited by sandos; 09-15-09 at 12:05 AM.
    09-15-09 12:02 AM
  2. Plazmic Flame's Avatar
    I know that they are selling iPhone 3G for cheaper now since the release of 3GS. I should be able to downgrade it with no problems if I go buy one now right?
    09-15-09 12:09 AM
  3. sandos's Avatar
    I know that they are selling iPhone 3G for cheaper now since the release of 3GS. I should be able to downgrade it with no problems if I go buy one now right?
    You can downgrade the OS on a 3G without doing anything like you need to do with the 3G[S]... However, if your aim is an unlock you will not be able to do so for a long time, or ever, if the modem firmware is at 05.11.07. This will be the case if the phone was ever updated to 3.1, and cannot be downgraded unless it has bootloader 5.08 (which is rare; only on pre 09/2008 devices)...

    In summary. Downgrade the Phone OS on a 3G, yes. Downgrade the baseband (the modem firmware), no.
    09-15-09 12:31 AM
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