some days ago I have been out shooting with my M9-P (latest firmware installed). I used the following SD card:
SanDisk Extreme HD Video – 8 GB
I have never had any problems using this card on any firmware with my M9. Everything worked like a charm until this time. After the shoot reviewing the pictures on the camera was fine. I went to my Mac Book Pro and inserted the card into my external USB card reader device and nothing happened. Well the indicator LEDs on the card reader blinked but nothing else. Several remove/reinsert and unplug/replug actions have been without any result. So I put the card back to the camera and it could not read it either. What to do now?
After googling a bit I decided to try Apples on board disk utility to repair the partition, but it exited with errors as well. So I downloaded 3 restore programs from the internet and tried them out. I will only highlight the one which luckily rescued my pictures:
Disk Drill – free edition
With this tiny program you can kind of produce a disk image from the not readable partition. After that you simply mount it and copy the files away. The neat thing is that there is – as far as I have seen – no limitation in the amount of MBs you can rescue. Other free software will show you all your vanished files and let you restore 10 MBs and force you to buy the pro version …
So seems like that there are still problems with some SD cards …
Bottom line: I saved about 98% of my files (the lost ones have been in the middle) thanks to Disk Drill. After the rescue action I formatted the card using the disk utility and now it is again readable/writeable by the camera and computer, though I will use it in future with a grain of salt.
Hint: If you open the M9’s bottom plate and you hear a beep this indicates that the camera is switched on. In this case turn the camera off before removing the SD card. Removing the card while there might be still read/write actions could also lead to data problems.