Accidentally updated to 6.0. Can i still restore my nand ?

Discussion in 'Switch - Exploits, Custom Firmwares & Soft Mods' started by Rojagfo, Sep 25, 2018.

  1. Rojagfo
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    Rojagfo Newbie

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    Long story short i updated my system. i want to restore my nand so i can go online again,is it safe to restore my nand now ?
    BTW : i backed up my nand back when it was 5.1.0.
     
  2. nekojosh

    nekojosh GBAtemp Regular

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    It depends if you did the upgrade with efuse protection. If your efuses are burnt then, afaik, you can't roll back.
     
  3. Rojagfo
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    Rojagfo Newbie

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    dammit, so what can i do now ?
     
  4. 8BitWonder

    8BitWonder Small Homebrew Dev

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    Boot into hekate and check your fuse count under system info.
    If you have 6 burnt fuses, then you can safely downgrade back to 5.1.0 with your backup.
    If you have 7 burnt fuses, then you cannot safely downgrade back to 5.1.0. (At least not without always disabling fuse checks)
     
    Last edited by 8BitWonder, Sep 25, 2018
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  5. ScarletDreamz

    ScarletDreamz [Debug Mode]

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    If you accidentally updated, then you pretty much did not do it using the efuse method.

    So no, cant do anything atm.
     
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  6. nekojosh

    nekojosh GBAtemp Regular

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    How do you always disable fuse checks?
     
  7. 8BitWonder

    8BitWonder Small Homebrew Dev

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    By always booting with hekate or any other bootloader that disables them.
     
  8. RHOPKINS13

    RHOPKINS13 Geek

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    Basically, you can downgrade, but you'll always need to boot using a payload to skip the fuse checks.
     
  9. jakkal

    jakkal GBAtemp Addict

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    Accidentally updated...lol

    If you updated using the Homebrew tool then you can downgrade, but since you accidentally did it, I bet you downloaded it from Nintendo .

    So no, you can't downgrade
     
    Last edited by jakkal, Sep 25, 2018
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  10. Rojagfo
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    Rojagfo Newbie

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    Does that mean that i can restore my nand then update again ?
     
  11. jakkal

    jakkal GBAtemp Addict

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    Check how many burnt fuses you have before trying to downgrade
    Unless you want a brick
     
  12. Rojagfo
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    Rojagfo Newbie

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    Checked i have 7 burnt fuses
     
  13. jakkal

    jakkal GBAtemp Addict

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    You can't downgrade. Don't listen to anyone who says otherwise
     
  14. 8BitWonder

    8BitWonder Small Homebrew Dev

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    Then you are no longer able to boot into your 5.1.0 backup as though it were stock.

    If you decide to restore your backup anyway (I advise against this), you must always boot through hekate or another bootloader that disables fuse-checks.
    Otherwise your system will panic at boot and turn off whenever you aren't disabling fuse-checks.
     
    Last edited by 8BitWonder, Sep 25, 2018
  15. raphamotta

    raphamotta GBAtemp Advanced Fan

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    Really? Hekate can disable fuse checks?
     
  16. 8BitWonder

    8BitWonder Small Homebrew Dev

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    Yes, it's the reason why we can safely update to higher firms and then downgrade later.

    We upgrade with ChoiDujour(NX), and then when we boot with hekate it disables writing/reading of the fuses to let use boot properly, without locking us to the latest firm.
     
  17. raphamotta

    raphamotta GBAtemp Advanced Fan

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    AFAIK Hekate can boot higher FW without burn fuses, but can't boot lower FW if you have more fuses burned than it requires. (Sorry if I'm wrong )
     
    Last edited by raphamotta, Sep 25, 2018
  18. 8BitWonder

    8BitWonder Small Homebrew Dev

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    I'm pretty sure it disables both checks and burning, but I'm not in a position to test it at the moment.

    Though I think it's fair to say even if it does support booting lower firms than your fuse count would allow, it's probably best not to.
     
  19. ZachyCatGames

    ZachyCatGames GBAtemp Maniac

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    Hell
    You can restore it, but you would have to use a bootloader that disables the fuse checks, and also sleep mode wouldn’t work
     
  20. Draxzelex

    Draxzelex GBAtemp Guru

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    In my testing of ReiNX, I downgraded my console with 5 burnt fuses down to firmware 3.0.2 without any issues so yes, bypassing the fuse count goes both ways: both for counts above and below your current count.

    P.S. Sleep mode doesn't work on firmwares 3.0.X with ReiNX (may or may not be related to that same issue on SX OS as of V2.0;) )
     
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