I'm troubleshooting a Tapo doorbell that stopped working after it was recharged. It had been using a 64GB Patriot SD card formatted as FAT32, with several recordings stored on it. The camera appears to work only after removing the card, so I'm trying to determine whether the card is the problem.
Windows allows me to delete files from the card, but they reappear after refreshing File Explorer. I also can't format it: both quick and full formats fail. Running `chkdsk H: /f` reports no file-system problems but ends with "Cannot write boot sector." I can copy new files to the card, but they disappear after ejecting and reconnecting it.
I've tested two different SD card readers, both of which have worked reliably before. The card is only a few months old, so I'd like to know whether it has failed, entered a read-only state, or whether there's another troubleshooting step worth trying tonight before replacing it. The camera monitors a motorbike, so getting it working temporarily would be useful.
2 Answers
You can try the official SD Association Formatter as a last recovery attempt. It may handle the card differently from Windows’ formatter, although it can take a long time and it cannot repair hardware that has permanently locked itself read-only. If it also fails, the card should be considered unreliable and shouldn’t be used for security footage.
The card has most likely failed and switched itself into a read-only safety mode. Flash cards do this when their controller detects that they can no longer reliably write data, which explains why deleted files return and why new files vanish after ejecting. A card being only a few months old doesn’t rule out an early failure, so check whether it’s still under warranty and replace it with a reputable high-endurance card for continuous camera recording.
That’s disappointing given its age, but the read-only behavior does seem to match what I’m seeing. I’ll check the purchase warranty before replacing it.
A so-called low-level format won’t truly repair failing flash memory; it’s worth trying only as a final test, not as a dependable fix.