Mac Says the SD Card Is Not Readable: Recover the Family Videos Before Repairing It
Recover the videos before trying to repair the SD card again. If commercial recovery apps can already list the AVI files, do not format the card or keep running First Aid just to make it mount normally. The immediate problem is getting the files off with the least additional writing to the card.
In this Mac SD-card recovery case, the card contained old family movies from the user's late father. It was pulled from a MacBook Air while QuickTime had a video open. macOS then reported that the disk was not readable; Disk Drill and R-Studio could see the AVI files but required payment; PhotoRec initially did not see the card; and Disk Utility First Aid reported an Invalid BS_jmpBoot boot-block error.
Why PhotoRec May Not Be Listing The Card
Before assuming PhotoRec cannot recover the card, check whether macOS exposes the physical device at all. CGSecurity's current macOS instructions say TestDisk and PhotoRec need low-level disk access; if no disks are listed, grant Terminal or the recovery app Full Disk Access in Privacy & Security. Their documentation also recommends selecting the raw /dev/rdisk* device when available on macOS.
- Step 1
Open Disk Utility with View > Show All Devices, or use the read-only
diskutil listcommand, and confirm that the SD card appears with approximately the correct capacity. - Step 2
If the physical card is listed, follow CGSecurity's macOS access guidance, then retry PhotoRec against the card's raw device. Save recovered files to the Mac or another external drive, never back to the SD card.
- Step 3
If the physical card is not listed at all, or it disconnects during reads, free recovery software has no stable source to scan. Test another known-good reader once; if detection remains unstable and the movies are irreplaceable, stop DIY and consider a recovery lab.
Use PhotoRec For Recovery, Not A Repair Command
PhotoRec is free and open source and can carve files from a corrupted filesystem without first repairing it. The tradeoff is that recovered files may lose their original names and folder structure. For family AVI videos, that is usually preferable to modifying the only copy of the card before the data is safe.
TestDisk also includes FAT/exFAT boot-sector repair functions, but CGSecurity warns that filesystem repair can remove invalid entries. Do not use those repair features until the videos are recovered to another device.
About Truly Free Recovery:
Recoverit Memory Card Recovery is a valid scan option while the card is stably detected, but its current Mac free edition is limited to up to 500 MB of recovered data. For several AVI family movies, that may not satisfy a “fully free” requirement. In this specific case, fixing PhotoRec's disk-access problem is the better free-first path.