Back up before any test

If files remain accessible, copy them immediately to separate storage. Filesystem checking or repair may write to the card; it must not precede backing up important data.

If the card disconnects, becomes unusually hot or very slow, or produces input/output errors, stop. No software procedure guarantees recovery.

Corruption, false capacity or incompatibility?

Possible cause	Signs	Useful evidence
Logical corruption	Unreadable files or folders, filesystem errors	A checking tool’s report after backing up
False capacity	Writes work initially, but data becomes corrupted beyond a threshold	A complete read/write test on an empty card using a reliable tool; this is destructive
Incompatibility	The card works elsewhere but the device does not mount it	Device documentation, correct format and partition scheme, comparison tests
Physical failure	Disconnections, repeated I/O errors, unreadable data	Persistent failure across several readers or computers strengthens the suspicion without proving physical failure by itself; consider backing up and replacing the card.

Preliminary checks and possible repair

• Try another card reader and another port.
• Identify the exact drive and its reported capacity.
• Copy readable data to separate storage.
• Check mount status and errors without reformatting.
• On macOS, First Aid checks and may repair the filesystem: it is not read-only. Run it only after verifying a backup and correctly identifying the storage device; it does not detect or repair every fault.

Check capacity and errors

The capacity shown by the operating system does not by itself prove that the physical memory exists. A full capacity test writes and reads back the entire space. Prepare an empty card after verifying your backup: depending on the tool, some steps erase or overwrite existing data.

Without a documented full test, describe false capacity as suspected, not confirmed.

Reformat only when justified

Formatting is appropriate for a backed-up, physically stable card when the format or partition table is the problem. SD Memory Card Formatter formats a card according to the SD standard, but does not repair worn-out memory or identify a counterfeit by itself.

Then choose the format required by the device. For TF2 under the current dArkOSRE procedure, the documentation specifies exFAT; the system card instead needs the complete disk image.

When to replace the card

• Repeated input/output errors.
• Disconnections with several readers.
• Full capacity cannot be verified.
• Corruption returns after a clean format.
• A generic original card holds the only copy of important data.

R36S: TF1, TF2 and screen panel

TF1 holds the system; TF2 is optional for games. A missing TF2 is a different problem from a black screen on first boot. Check the active storage, format and switching script before blaming the card.

An incorrect DTB or panel profile can cause a black screen with a perfectly readable card. Card health and the hardware profile are two separate diagnoses.

Limits and unrecoverable data

If no copy is readable and the data is irreplaceable, stop destructive tests. This guide helps you decide what to do; it does not replace a data-recovery laboratory.