About removing B9S and the safety test

Discussion in '3DS - Flashcards & Custom Firmwares' started by KleinesSinchen, Jun 24, 2019.

  1. KleinesSinchen

    KleinesSinchen The Backup Reminder

    Mar 28, 2018
    Removing B9S is unnecessary, potentially dangerous for your console and has no benefits at all. This can’t be said often enough. Best explanation in “You don’t need to remove B9S”[…] by Lilith Valentine.

    Yes, I know: I want virginity back.” … the most frequent reasons for uninstalling B9S are:

    A) I want to sell the system!
    While I understand the idea behind that (a random buyer not knowing about hacks might do stupid things, complain about the hacks, demand a refund and whatnot) it is still not a wise decision. Find a (private) buyer who accepts or even wants a modded console and explain it to them. You are not gonna get rich by selling a used 2/3DS anyway.
    B) "I'm so afraid of being banned from online play!"
    Opposed to the situation on the Switch, Nintendo either can't reliably detect CFW or does not care about it (anymore) or both. The pretty much only way to get banned is cheating online (since there are no new games anymore that could be illegally obtained and played before official release in case of a leak). If there is a way for Nintendo to detect CFW, removing it, will not remove that "flag". Long story short: CFW does not lead to a ban and removal of CFW would not prevent a ban.​

    An even worse situation is when you are the buyer of a modded console and have no clue what B9S, Luma, GodMode9… are. If you did not mod the system yourself but got it premodded you have virtually no idea what has been done to a 2/3DS. (In the sense: "You do not understand these things." and in the sense "You have no idea if the seller modified system components.")

    :!: If you just got a modded 2/3DS console and have no clue what to do next: “Delete everything for a fresh start!” is the absolute worst thing you can do.

    The good news is: You will find all help you need here on the forum.

    Often opinions and statements like this one can be found (not an actual quote; just an example) :
    For a long period there was no method of indicating if removing B9S would lead to a fully bricked 2/3DS which can only be revived by reinstalling B9S with ntrboot. Thanks to the safety test on the guide this problem is no more. Now with the safety test everything is fine… or not? NO! It is not! The test is very good! An extremely helpful idea preventing full bricks¹. But it does not ensure removing B9S has no bad side effects.

    Even if your console boots to the Home Menu when doing the safety test, there might be problems you will encounter after uninstalling the custom firmware. Problems that the short test (“Start Home Menu without signature patches”) does not show and even errors that can make reinstalling B9S through the "Miner"-methods impossible². A few examples:

    1: Bricked DS(i) mode

    I have no idea why this happens so often, but one thing is sure: It does happen. In the most cases this can be repaired by reinstalling the DSi CIAs (either by downloading them from somewhere or – like the guide now advises – by deleting the titles and doing a normal system update). Sometimes even CTRTransfer was needed for whatever reason.
    If your DS(i) mode is bricked and you did not notice it before uninstalling B9S, this will not affect the safety test. After uninstalling B9S you neither can delete the damaged titles nor reinstall CIAs from somewhere. And the "Miner" way of reinstalling B9S is blocked.²
    Tested by renaming the folder “title” on TWLN to “Sitle” → DS(i) mode fully broken, but safety test is successful.

    2: Super-bricked DS(i) mode
    If you happen to have your TWLN partition unusable, this does not affect the safety test as well. This can make normal System Updates impossible. If your device is not on the latest firmware – or Nintendo releases the next surprising “stability update”, you have successfully locked yourself out of any online functions – in addition to the borked DS(i) mode.


    I tried it by provoking a needed update for TWL titles while TWLN was super-bricked. The official updater got stuck at about 20%. I waited more than 10 minutes – no movement of progress bar – nothing.​

    3. Modified non-essential NAND-titles
    A 2/3DS may have modified (not signed!) titles which are not needed to boot, but will not work without signature patches. In this case the keyboard. There also can be some kind of leftovers like Flipnote Studio still injected into Download Play. To repair this you need “root privileges”.
    By uninstalling CFW, you lock the door, throw away the key and after that you now notice that you did not tidy up the house. In this case Flipnote Studio can – hopefully – be used to reinstall B9S.​

    4. Illegitimate titles making Data Management crash

    The uninstall section of the guide advises the user to remove any non-signed software before running the uninstall script. If you do not do this "Data Management" can be rendered unusable after running "Un-install Hax". This can be easily tested by opening all Data Management options while doing the safety test.​

    5. FBI injected into Health and Safety Information
    Very minor problem – at least for me. Removing CFW while FBI is injected into H&S (done e.g. via GodMode9 script) will render the pretty useless (my opinion) text showing app unusable.​

    If you are still dead set against keeping CFW on your device, at the very least do some more testing than simply booting Home Menu with NATIVE_FIRM (but do not test the official updater while running NATIVE_FIRM – in this case B9S is not protected and may be overwritten before you have tried out everything).

    If anybody has other ideas how to bring a 2/3DS into a state where removing CFW does not fully brick but has side effects, please explain it me so I can add it to the list.

    ¹ If you (or a previous owner) modified console unique data (such as SecureInfo_A, LocalFriendCodeSeed_B) or there are modifications on the Home Menu (different text or font or color – whatever), removing B9S (=only loading the official firmware without signature patches) will render the console useless.
    This is what the test simulates without actually removing B9S.
    ² This is not fully true anymore. The path "Seedminer → Homebrew Launcher (Pichaxx) →DSiWare Dumper" of the guide now includes the optional step of using a "userland homebrew"-only version of TWLFix3DS. However this is not guaranteed to work. Bricked DS(i) mode can have other reasons too. In this case a defective camera module seems to be the reason for not working DS(i) mode. EDIT: Example for successfully using TWLFix3DS without CFW: [I UNMODDED MY OLD 2DS AND NOW ITS MESSED UP.........(PLEASE HELP!)]
    Last edited by KleinesSinchen, Oct 18, 2019 at 3:20 PM - Reason: Example for userland TWLFix3DS
    peteruk, ry755, E1ite007 and 5 others like this.
  2. botik

    botik Member

    Sep 22, 2017
    In the risk group of the console with a changed region, movable.sed and LocalFriendCodeSeed_B.Before deleting CFW, all this data should be returned to the original otherwise get brick
  3. KleinesSinchen

    KleinesSinchen The Backup Reminder

    Mar 28, 2018
    That's the kind of changes the safety test can detect (and what makes the test indispensable) – It will freeze and not boot into Home Menu.

    Besides: Region changing and removing B9S is possible (but a really bad idea).
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