What to Do With a Corrupt Flash Memory Card

How depressing is this? You come off of a weeklong family reunion cruise where your family has been designated the photo archivists. A few days into the trip, when you go to move some photos off the memory card onto your PC, you find the card is corrupted. The images can be seen, but refuse to be copied to the PC.

You can:

1. Jump ship;
2. Confess to your family that there are no memories; or
3. Use the Internet to learn how to repair a corrupted disk.

I can't tell you much about how 1 and 2 might work, but here's an in-depth look at option 3.

First, a little back-story: I could see all of the photos when I browsed them with my camera's built-in preview. I just couldn't copy them to the computer. Luckily I had another memory card so I switched in mid-trip, but what to do about the lost photos?

The minute we arrived back home I tried every way of reading the suspect 2GB CompactFlash card. Several USB readers in several different computers later, and in each case the computer would complain that it couldn't read the root directory. I also tried a direct USB connection to the camera with the same result. But I could view all the pictures just like I could on the camera's LCD viewer on the cruise.

Turning to the web for help, I ran across Fred Wertheimer's web page. Fred says heat can be a problem for flash memory, and since I was in the Caribbean I was sure he was onto something. Fred recommended his top five flash memory recovery tools. I chose ZAR (Zero Assumption Digital Image Recovery tool) (the only free one, not coincidentally).

Actually, ZAR is free if you're using it to recover photos from memory cards; for other uses there is a charge.

ZAR spent the better part of an hour working on the disk, eventually recovering 482 valid images plus 17 trashed images. It was hard to compare what was missing with what I had because ZAR changes the order of the pictures, though it preserves the names. But my husband (called in because the going was getting tricky) and I determined that a few images and all of our video snippets were missing. ZAR came awfully close to perfection, but we decided to try some old PC recovery tricks now that we safely had most of what we'd feared lost.

CHKDSK used to get us by in the old days of DOS and floppies. It would check for and correct errors in unreadable files. CHKDSK remains a part of today's Windows though hardly used. To use it, we started a Windows command-line session (From the Start Menu chose RUN, then type CMD, and press OK) . Next we entered the command CHKDSK/F M.

The /F flag tells CHKDSK you want to fix problems, not just list them. This gives CHKDSK permission to make changes to the drive, which is necessary if the file structure has to be fixed. M: happens to be the drive name of my CompactFlash reader.

CHKDSK did a full analysis and corrected problems. Only one photo was unrecoverable and CHKDSK complained that there was a file with cross links (serious problems).

Funny how a relic of a utility from the heyday of DOS saved the day, isn't it? Read the next post for how to avoid getting yourself into this mess in the first place.