Last week my trusty (4 year old) 32 Gb Compact flash card developed a problem. It would format nicely in my DSLR camera but once in the computer it seemed corrupted. My Mac and my PC would mount it. The file system was too damaged.
It had photos I just shot and obviously would like to recover. The recovery tool from Transcend RecoverX was useless because it only works when you can mount your card. In my case it was too badly damaged. On the Mac it seems there are a few paid for software packaged (around 40 dollar) that seemed a bit too much for my one time need. On my PC after trying a few other, pretty poor software packages, I stumbled upon ZAR (Zero assumption Recovery). They have a Free version that allowed me to recover files from an unmountable CF card. It just scans block for block to see if it can find anything that looks like the file formats it knows. It found my CR2 files as TIFF but that was easy renamed later. So after about an hour I had my photos! Kudos to ZAR.
Oh and the good people at geheugen.com had my 4 year old CF card replaced under Life Time warranty within a few days. It is nice when getting warranty isn’t a hassle.