Cannot format SD card / cannot detect SD card

SD cards don’t usually advertise their SPI mode speed. Some cards may implement it badly or in some cases not implement SPI mode at all. This usually happens with fake and no name SD cards. I recommend Sandisk 16-32gb cards for Flippers. They fall in the sweet spot between quality and cost.

Flipper Zero works with the microSD card in SPI mode (instead of standard SDIO) so it is important to use high-quality branded microSD cards such as SanDisk, Kingston, etc. Fake cheap microSD cards can work badly in this mode.

did you ever get it to work? i have the same issues

Thank you all who suggested factory reset, that was exactly what was needed. I was starting to think I have a bad device because I tried a 32G Transcend, a 2GB no brand, 1GB Samsung and 1GB Sandisk and none were detected when inserted. I erased all of them on a PC and formatted them with FAT at which point the FZ could see most of them when inserted but still could not write to them or benchmark them.

Finally I googled and found this forum and after trying the factory reset option they all worked except the “no brand” one which is still not detected.

I’m very happy, thanks again.

They recommend staying away from no name brands. I’m glad you got this sorted! Have fun “Flipping” out!