Extracted from ctrcheck.gm9 from the NH server repo under MIT License.

NAND Checks

NAND Header

Error: NAND header is an invalid size.

Error: NAND header not found.

Information: NAND header's signature is sighax.

Information: NAND header is stock. (n3DS)

Critical: o3DS has an n3DS NAND header.

Information: NAND header is stock. (o3DS)

Critical: n3DS has an o3DS NAND header.

Warning: NAND partition table is modified, but there is sighax in the NAND header.

Error: NAND partition table is modified, and there is no sighax in the NAND header.

Error: NAND header data is invalid. You've met with a terrible fate, haven't you?

NAND Sectors

Warning: Secret Sector data is invalid. a9lh might be installed.

Warning: There may be a9lh leftovers in the secret sector.

Critical: NAND is unreadable at offset 0x12C00...?

Critical: TWL MBR data is invalid.

Critical: TWL MBR not found.

Critical: NAND is unreadable at offset 0xB800000...?

Warning: There are likely leftovers from a9lh's stage2 payload.

Information: Bonus drive is enabled.

CTR NAND

Error: CTRNAND not found.

movable.sed

Critical: movable.sed's copy of LFCS is blank.

movable.sed is misconfigured. Press (A) to reconfigure it to normal values.

Information: movable.sed has been fixed by removing the CMAC flag.
Critical: movable.sed is 288 bytes but has the CMAC flag.

Error: movable.sed is invalid, and essential.exefs does not exist. ( at recovery )

Bruh Moment: movable.sed is still invalid after a recovery attempt. ( after recovery attempt )

LFCS

Information: LFCS doesn't match movable.sed.

Error: LFCS is invalid, and essential.exefs does not exist. ( at recovery )

Warning: Console is using a donor LFCS.

Bruh Moment: LFCS is still invalid after a recovery attempt. ( after recovery attempt )

SecureInfo

Warning: SecureInfo doesn't match the console's region.

Information: Console's region is changed from ♦ to ♦.

Information: SecureInfo_C exists, but console's region is unchanged.

Error: SecureInfo is invalid, and essential.exefs does not exist. ( at recovery )

Bruh Moment: SecureInfo is still invalid after a recovery attempt. ( after recovery attempt )

HWCAL

Error: HWCAL0 is invalid, and essential.exefs does not exist. ( at recovery )

Bruh Moment: HWCAL0 is still invalid after a recovery attempt. ( after recovery attempt )

Error: HWCAL1 is invalid, and essential.exefs does not exist. ( at recovery )

Bruh Moment: HWCAL1 is still invalid after a recovery attempt. ( after recovery attempt )

Information: GodMode9 and Luma3DS are in the NAND.

Information: Luma3DS is in the NAND, but GodMode9 isn't.

Warning: Luma3DS is not in the NAND. (This console cannot boot without an SD card.)

Critical: CTRNAND title.db data is invalid.

Critical: CTRNAND title.db is an invalid size.

Critical: CTRNAND title.db not found.

Recovery

Critical files in the CTRNAND are invalid, but a backup was found. Press (A) to enter data recovery mode. (If you have already tried this recently, you may safely skip this part.)

In case of refusal:

Error: movable.sed is invalid, and data recovery was denied. Error: LFCS is invalid, and data recovery was denied. Error: SecureInfo is invalid, and data recovery was denied. Error: HWCAL0 is invalid, and data recovery was denied. Error: HWCAL1 is invalid, and data recovery was denied.