New 3DS with CFW won't turn on: Blue light simply turns on then back off

There's a problem reading the Luma3DS boot.firm, or the boot.firm is not compatible with your setup. Delete boot.firm from the root of your SD card and replace it with 10.0.1 (or redownload 9.1 if you want). If it doesn't work, do it with 7.1. If that doesn't work, do 7.0.5.

If none of that works, reformat your SD card and retry the above steps.

 

Sigh, person #7. Don't skip anything.

• CFW: I formatted my 2ds's sd card and now it wont turn on [post #17]

If it boots SafeB9SInstaller, go ahead and update to the latest boot9strap v1.3 to ensure your current B9S isn't outdated.

Complete the CTRNAND Luma3DS for booting without SD card.

If you want to use multiple FIRM payloads, like have both Luma v9.1 and v10.1, etc, you can later substitute boot9strap with fastboot3ds once everything is up and running again.

 

If the SD is removed, then that's to be expected. It can't read the Luma3DS boot.firm from the SD card if the SD card is missing.

Once everything is working again, you need to put the Luma3DS boot.firm onto the CTRNAND so it can boot without the SD card.

 

Did you format the SD using guiformat?

 

What program did you use to reformat your SD card? What settings were used on that card? Was your empty card hardware tested with H2testw? Did you add both Luma3DS v7.0.5 arm9loaderhax.bin and SafeB9SInstaller renamed as boot.firm?

 

The SD Association's SD Memory Card Formatter is used to revive softlocked or badly formatted SD cards not recognized by Windows File Explorer, so long as the underlying fault is software based. It can also be used on other flash memory including USB pen drives, Compact Flash, Memory Stick, etc. That program doesn't have the fine tune control reformatting SD cards to be compatible with the 3DS, especially for cards larger than 32 GB.

Because it's possible to badly reformatted an SD card that is detectable in [Windows / Linux / Mac] but unreadable or even perform poorly with slow read/write speeds on the 3DS, I suggest you start over with the quadruple reformatting technique with all four (4) of those programs in that specific order to avoid this scenario.

Side Note
If your card is 128 GB or larger, you can elect to use 64 KB (65536) cluster size as long as GBA VC, theme shuffle, FTP, and FBI-Bloop works out for you.

• Weird Problem W/ GBA Injects (VC on 3DS)
  • And the bunch of other threads in the "References regarding GBA VC graphical glitch bug" spoiler.
• Doesn't FBI - Remote Install work with SD cards >64 gb?

Do not use 64 KB cluster size on 64 GB or smaller card.

***

Once you quadruple reformat, continue on with step 3 in the previously mentioned post.

 

Have you tried using a different SD card?

 

Have you actually used the h2testw test to confirm your sd card isnt corrupt or fake? Everyone seems to take that for granted that since its new its fine. Well since technology aint perfect. There is never a guarantee that its working flawlessly. And for your case. Its something you should want to check.

 

Test both of them with H2testw: https://3ds.guide/h2testw-(windows)

Until you do, no one can give you any other advice because we'll just assume your cards are defective or fake.

Also, if you bought the cards from ebay, or an Amazon third party seller, or from a website that isn't associated with a brick and mortar store, there's a high likelihood of them being fake cards, or at least poor quality enough to start getting corrupted quickly.

 

This isn't a typical error message. Are you using a (micro/standard) SD card-to-USB adapter like this, or is the computer you're using really old like Windows 95, 98, 2000?

Bad reader adapter can derp mid read or write. Older computers have SD/MMC slot readers that don't support reading cards larger than 32 GB.

 

It's possible for the micro-to-standard SD card adapter like this to fail from worn out contact pins. However, most of the time the computer will outright fail to communicate with the card if connection is bad.

(Micro)SD-to-USB card reader are also known to fail like in this example. Failure from adapter is more sinister as there are no clear indications of data corruption until it's too late.

• Is my SD card faulty [post #10]

It's best to default to using the computer's built-in SD slot reader whenever you can so to reduce points of failure.. If your computer supports USB 3.0 speeds or doesn't have a SD slot, try to buy high quality card USB adapters buy like this Anker brand.

***

If you can do at least one clean scan run on an initially empty card in H2testw with no reported errors, that means the problem is not [directly] your card. It's most likely bad reader writing corrupt data. Try another SD card reader on a different computer if you can, and redo the quad reformat on that computer until your replacement SD-to-USB adapter arrives.