Memory Card Corruption

Anyone ever have this happen? I have a Canon 50D and was shooting out in relatively warm environment(85-90F) and suddenly the camera locked up. I pulled the battery and put it back in and the camera worked until I tried to take a picture. At this point it would take the shot and then lock up when trying to write to the memory card.

The same thing would happen if I tried to do any operations that access the memory card(preview images button for example). Because I had a number of shots on that card that I definitely didn't want to lose I put that card away and went on to another. The camera proceeded as normal.

When I got back home I tried first just to load the card. Windows often reported that it wanted to format it(which I obviously didn't let it do). I tried using an external card reader, the camera, etc without success. Eventually I realized that, upon inserting the card into the card reader, I could navigate the file structure of the card UNTIL I tried to open certain image files.

In the end about 10 pictures were unreadable and if I tried to copy them or open them, the card would no longer be readable by windows. Provided I did not copy those, the rest of the images copied over fine.

Now the real question. I would still like to save those images if possible...however, I have yet to find anything that can recover these RAW files. I first tried Sandisks recovery utility provided with their extreme IV cards(what I use) which reported there were absolutely no files to recover. Then I tried Zero Assumption Recovery. This program scanned the card but reported all the memory blocks as having faults. My guess is that it accessed one of the image files that locks up the card and then fails after that.

So I have yet to find a way to recover the images. I can see the files in windows, I just can't touch them. If I try to copy them or open them, it will fail and I will have to remove and reinsert the card.

If anyone has experienced this issue before I'd like to know if you were able to recover the pictures and how. It's not absolutely critical, as I saved about 170 of 180 pictures just by "avoiding" the bad ones. However, I don't exactly know what was in those last ones and it kills me knowing that it might have been a favorite.

Thanks in advance and I apologize for the long explanation.

You're seeing the image file names because that is stored in the directory structure. The actual files appear to be corrupted. So there's little likelihood that you will be able to read them. On the other hand, if the problem is the directory structure pointing to the wrong place, the data may be good, but there's no way to get to it. It might be possible to get a raw data dump from the card. However, then you'd have to find the files amidst all that hexadecimal code. It's not an encouraging picture, I'm sorry to say.

Check another card to make sure that your camera is not writing corrupted files. Otherewise, trash the card or send it back to Sandisk for a replacement. Aren't the Extreme IVs warranted for life.

Make sure you format the card before each use. Don't just delete the files. The file structure can get fragmented otherwise, which will slow down the reading and writing processes.

joedlh wrote in post #9251510
You're seeing the image file names because that is stored in the directory structure. The actual files appear to be corrupted. So there's little likelihood that you will be able to read them. On the other hand, if the problem is the directory structure pointing to the wrong place, the data may be good, but there's no way to get to it. It might be possible to get a raw data dump from the card. However, then you'd have to find the files amidst all that hexadecimal code. It's not an encouraging picture, I'm sorry to say.

Check another card to make sure that your camera is not writing corrupted files. Otherewise, trash the card or send it back to Sandisk for a replacement. Aren't the Extreme IVs warranted for life.

Make sure you format the card before each use. Don't just delete the files. The file structure can get fragmented otherwise, which will slow down the reading and writing processes.

The other cards used for the remainder of the trip worked fine. I doubt that this error had anything to do with the 50D but it rather seems linked to a faulty write to the memory card. You do bring up a good point of whether or not I trust the memory card after a format to work properly now.

Hi,

A few questions...

Was the card ever used in another camera, most particularly something other than a recent Canon camera? I ask because a friend borrowed a card or two from me to shoot with her Nikon and when I later put those cards back in my camera, it really didn't like them! I ended up formatting the card in computer then formatting it again in my camera.

Which brings me to another question... Do you always format your cards in camera before shooting with them? I've gotten in the habit of doing that and have had very few problems.

Now a couple other possibilities....

Once I pulled a card from a camera too quickly, while it was still writing. Not only the last image but about a third of the other 250 or so images on that card were unrecoverable. I used Lexar's image recovery software to get back what I could. I ran Sandisk's and another one on the card, too, but didn't manage to get any more images.

Maybe your camera lost power for some reason in mid-write, which would certainly corrupt the image being written, but tends to cause issues with some other images filed on the card, too.

One thing I've seen on rare occasion with 30D in the past was a sudden lockup and loss of all power due to a slightly loose battery grip. I haven't had that happen with 50D, but I image it could happen. I've simply shot a lot more over the years with 30D than with 50D.

Another thing, I have heard and read that memory cards actually often have some "bad sectors". They are solid state devices so it's pretty rare for a good sector to "go bad", more typically it's bad sectors right from new. Manufacturers deal with this by actually building a bit of headroom into their memory cards, then mapping around the bad sectors with software (essentially marking those sectors to not be used by any device the memory is installed in). The extra headroom allows them to still offer a card that's fully up to spec. By doing this they are able to offer memory cards at lower cost, since there is less waste during the manufacturing process. (I'm no expert on such things... this is just something I've seen and heard reported... my explanation might be overly simplistic!)

One of the softwares I have (Lexar's Image Rescue, I think) has a utility that will test and analyze a memory card, map any bad sectors, and mark them in the same way as above. I don't recall if Sandisk's rescue software will do this, too.

Chances are, those ten images are unrecoverable. But, you might try any other free image rescue softwares you can find before formatting your memory card (I'd do it first in computer, then again in your camera).

If they are extremely important images, there are companies that specialize in rescuing data from various types of storage devices. They might or might not be any more successful than you, though.

Is this a SanDisk Extreme IV card or were you just using their software? If not a SanDisk card what type of card?

K6AZ wrote in post #9251582
Is this a SanDisk Extreme IV card or were you just using their software? If not a SanDisk card what type of card?

Yes it was a SanDisk Extreme IV card. I bought 6 8GB cards when I got my camera last fall.

There's a fault with a batch of 8GB Extreme IV cards, perhaps this is your problem? See announcement here on Sandisk forum...
http://communities.san​disk.com …=extreme4cf&thr​ead.id=287

Rob

RobKirkwood wrote in post #9251810
There's a fault with a batch of 8GB Extreme IV cards, perhaps this is your problem? See announcement here on Sandisk forum...
http://communities.san​disk.com …=extreme4cf&thr​ead.id=287

Rob

That's what I first thought when I saw EX iV 8GB mentioned. A 'handful' of complaints? Must be a really big hand.

K6AZ wrote in post #9251835
That's what I first thought when I saw EX iV 8GB mentioned. A 'handful' of complaints? Must be a really big hand.

Wow thanks for pointing this out guys. I am definitely going to see if ANY of the cards I bought were affected by this.

Real shame too because I bought the extreme IV series partially because I wanted to best in speed AND reliability. Never had a issue with corruption like this before...even on cheap cards.

You guys win! The card that failed was a 905 card. The rest are 906's. Damn I wish I had found this out earlier....oh well better late than never.

Sdiver2489 wrote in post #9253593
You guys win! The card that failed was a 905 card. The rest are 906's. Damn I wish I had found this out earlier....oh well better late than never.

Sorry you got stuck with one. They will replace it but unfortunately the shots you put on it are probably lost.

amfoto1 wrote in post #9251571
Hi,

A few questions...

Was the card ever used in another camera, most particularly something other than a recent Canon camera? I ask because a friend borrowed a card or two from me to shoot with her Nikon and when I later put those cards back in my camera, it really didn't like them! I ended up formatting the card in computer then formatting it again in my camera.

Which brings me to another question... Do you always format your cards in camera before shooting with them? I've gotten in the habit of doing that and have had very few problems.

Now a couple other possibilities....

Once I pulled a card from a camera too quickly, while it was still writing. Not only the last image but about a third of the other 250 or so images on that card were unrecoverable. I used Lexar's image recovery software to get back what I could. I ran Sandisk's and another one on the card, too, but didn't manage to get any more images.

Maybe your camera lost power for some reason in mid-write, which would certainly corrupt the image being written, but tends to cause issues with some other images filed on the card, too.

One thing I've seen on rare occasion with 30D in the past was a sudden lockup and loss of all power due to a slightly loose battery grip. I haven't had that happen with 50D, but I image it could happen. I've simply shot a lot more over the years with 30D than with 50D.

Another thing, I have heard and read that memory cards actually often have some "bad sectors". They are solid state devices so it's pretty rare for a good sector to "go bad", more typically it's bad sectors right from new. Manufacturers deal with this by actually building a bit of headroom into their memory cards, then mapping around the bad sectors with software (essentially marking those sectors to not be used by any device the memory is installed in). The extra headroom allows them to still offer a card that's fully up to spec. By doing this they are able to offer memory cards at lower cost, since there is less waste during the manufacturing process. (I'm no expert on such things... this is just something I've seen and heard reported... my explanation might be overly simplistic!)

One of the softwares I have (Lexar's Image Rescue, I think) has a utility that will test and analyze a memory card, map any bad sectors, and mark them in the same way as above. I don't recall if Sandisk's rescue software will do this, too.

Chances are, those ten images are unrecoverable. But, you might try any other free image rescue softwares you can find before formatting your memory card (I'd do it first in computer, then again in your camera).

If they are extremely important images, there are companies that specialize in rescuing data from various types of storage devices. They might or might not be any more successful than you, though.

All good points, and one more most never respect, ESD. Static discharges can and will destroy both cards and data.

Image One is a great app. Low level formats can sometimes resolve issues that otherwise render a card unusable. Never use a know defective card.

I've seen hhd's become unreadable from data corruption. You can't even access them to format, but they will take a DOS level low format.

K6AZ wrote in post #9253650
Sorry you got stuck with one. They will replace it but unfortunately the shots you put on it are probably lost.

Yeah it sucks but at least I recovered most of the files(90+%) I can only imagine the horror I would feel if this was a wedding I was shooting.

While I was on the phone I remembered that there were two more cards I didn't use on the trip...turns out another 905 was in there. So I got two cards going back to Sandisk.

Here's the kicker....after I said that "I must be really unlucky" to the Sandisk Rep on the phone he responded with this jewel:

"No sir you are not unlucky instead consider that you just won the lottery because you will get 60MB/s card in replacement"