1. kenaroni's Avatar
    Hey All,

    iPhone 3GS on T-Mobile
    IOS4.0, jailbroken this year with Jailbreakme.com
    Newer baseband, forget the version#
    Blobs are saved, using an iMac.

    Having weird problems with my iPhone 3GS occasionally powering off in the blink of an eye. Possibly a battery issue, wants power source to boot back up. Anyways, I thought that upgrading to 4.1 might clean it out and fix the problem?

    I've used Pwnage tool before on an iPhone 2G so I know about DFU mode. But my 3GS simply will NOT go into DFU mode, even after trying like 50 times, slightly varying my button hold-down times. Keeps going to recovery mode instead. Just for fun I tried it while not connected to the cord and it seemed to go right into DFU with no problem. Has anyone heard of this?

    Some say you don't need DFU mode for a previously jailbroken phone, just use recovery mode with your cooked IPSW restore file. I tried that but iTunes fails to install it, giving me a #1600 error every time. I've given up and gone back to my cheap Nokia for a while. Any ideas?
    2010-11-05 09:22 PM
  2. Mes's Avatar
    Yes! DFU mode IS required because PwnageTool/new Redsn0w injects code to fool iTunes into accepting a custom firmware ipsw.

    I've found that holding both buttons a bit longer than 10 secs (maybe 11 or 12) still works .... while releasing the Home button too early is not good.
    2010-11-05 09:32 PM
  3. iYeow's Avatar
    Hey All,

    iPhone 3GS on T-Mobile
    IOS4.0, jailbroken this year with Jailbreakme.com
    Newer baseband, forget the version#
    Blobs are saved, using an iMac.

    Having weird problems with my iPhone 3GS occasionally powering off in the blink of an eye. Possibly a battery issue, wants power source to boot back up. Anyways, I thought that upgrading to 4.1 might clean it out and fix the problem?

    I've used Pwnage tool before on an iPhone 2G so I know about DFU mode. But my 3GS simply will NOT go into DFU mode, even after trying like 50 times, slightly varying my button hold-down times. Keeps going to recovery mode instead. Just for fun I tried it while not connected to the cord and it seemed to go right into DFU with no problem. Has anyone heard of this?

    Some say you don't need DFU mode for a previously jailbroken phone, just use recovery mode with your cooked IPSW restore file. I tried that but iTunes fails to install it, giving me a #1600 error every time. I've given up and gone back to my cheap Nokia for a while. Any ideas?
    That is correct, once your iphone has been jailbroken by CFW, you can put it in recovery mode and restore to CFW again.
    2010-11-05 10:47 PM
  4. Mes's Avatar
    That is correct, once your iphone has been jailbroken by CFW, you can put it in recovery mode and restore to CFW again.
    Didn't work for me (3G and 3GS old bootrom both prior PwnageTool CFW). Barely got started before an error.

    But w/PwnageTool DFU mode, worked 1st time on both.
    2010-11-05 10:50 PM
  5. iYeow's Avatar
    I have the oldbootrom too, once i have installed custom firmware on mine, whenever there is a new custom firmware i need to upgrade, all i do is put my iphone into recovery mode and restore again.

    Of course you must also update your itunes to accomodate the newer firmware.
    Last edited by iYeow; 2010-11-06 at 08:12 AM. Reason: Automerged Doublepost
    2010-11-06 08:12 AM
  6. Mes's Avatar
    ^^Maybe iTunes is the key . On the other hand, there are many discussions & indications from the Dev-Team blog, twitter, the new Redsn0w, Pwnstrap (PwnStrap), etc about using DFU mode for injecting special code for iTunes. Without more details, I must assume DFU mode is necessary for most.
    2010-11-06 06:24 PM
  7. iYeow's Avatar
    The Redsn0w DFU mode is necessary for using the Geohot bootrom exploit. It is easily done, I don't know why people having problems getting into DFU mode using Redsn0w.
    2010-11-06 10:13 PM
  8. eyeRobot's Avatar
    Once you are on custom firmware you don't need DFU or recovery - at least I never did it just worked fine presumably because the exploit is already applied.

    I don't know if it's the same with the new limerain exploit pwnagetool when we upgrade to 4.2, but never had a problem getting it into DFU anyway.
    2010-11-07 05:50 AM
  9. Simon's Avatar
    Once you are on custom firmware you don't need DFU or recovery - at least I never did it just worked fine presumably because the exploit is already applied.

    I don't know if it's the same with the new limerain exploit pwnagetool when we upgrade to 4.2, but never had a problem getting it into DFU anyway.
    Because of the way the geohot bootrom exploit is used right now that doesn't apply to the current crop of custom firmware. That was the case before with the old bootrom exploit though. With this one the device has to be put into the special dfu every time to restore to a custom firmware. You can't simply have it in regular mode or restore mode and do it. It is all to do with the untethered part of the current jailbreaks. In the future it may go back to the old way of the "jailbreak train".
    2010-11-07 06:12 AM
  10. kenaroni's Avatar
    Thanks everyone. This is all good to know because I've read differing opinions about needing DFU mode or not.

    And this is AMAZING: After not having any luck at all updating to IOS 4.1 with my older PPC iMac at home (running Leopard), I decided to bring the iPhone to work and try it on my big Intel iMac running Snow Leopard. Ran PwnageTool and the iPhone went into DFU mode on the first try! Installed the custom IPSW smoothly and it just finished seconds ago as I type this. Screenshot below to prove it.

    Lesson learned: Always have a couple of different computers available when jailbreaking/updating, because one setup might cooperate better than the other.
    Last edited by kenaroni; 2010-11-07 at 04:11 PM.
    2010-11-07 04:06 PM
  11. Mes's Avatar
    Congratulation kenaroni. And I agree totally. More than 1 computer sure helps out a lot.

    And ... Thanks x98car (and yeow202) for more DFU mode details.
    2010-11-07 04:18 PM
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