I have a transcend 16GB SDHC card and a lot of photos on it that I'd like to recover. When I plug it into the SD card reader, it takes a while for the Mac to even recognize that there's a disk present, and it shows up as 1.07GB with geometry 520/64/63 (according to fdisk).

First I tried file recovery:

• PhotoRec: no files are found (the images are in CR2 format and I'm using testdisk-6.14-WIP which claims to recognize that format under TIF)
• dd / ddrescue: they create a 1.07GB image, same problem as above
• TestDisk: doesn't find any partitions to recover

I found a source saying that the correct geometry for this type of SD Card is Heads 255, Sectors/Track 63, Cylinders 1953, so I tried manually setting that geometry in PhotoRec/TestDisk. No improvement.

Next I tried formatting the disk with fdisk. After writing and quitting, I ran fdisk again and it reported that the new format hadn't been saved on the disk. I also tried resetting the format/partitions with TestDisk and that failed also. The fdisk log is below.

I don't really care about the card, I've already ordered a new SanDisk card. But I'd like to get the data off. Maybe, is there any way to force dd or some other tool to create an image of the disk based on the original geometry and not on what the card "thinks" its geometry is? Or am I missing something?