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|Sep 28, 2003, 11:08 AM||#1|
Join Date: Sep 2003
Memory Card Problems
I've had two instances where a memory card didn't work properly when I got home and tried to transfer the images to my PC.
In the first instance, I "knew" I was missing some photos, and tracked it down to one particular card, that had less images on it than I should have. When neither the camera nor the computer could retrieve the images, I decided I had nothing to lose, and loaded it back in my card reader, then ran Microsoft Scan Disk on it. That program "found" the missing images, and fixed everything so I could retrieve them. Good information to know.....
The second instance was worse. It was my brother's card. The card "said" the images were there, but there was an error whenever I tried to retrieve all but the first five or six images. Having given up on everything else, I tried Scan Disk. Scan Disk said there were all kinds of problems on the card, and took forever, finally saying it couldn't fix the problem. When we finally found we couldn't get back any more images, I gave up and tried to format the card - which I couldn't. Neither my computer nor the camera could format it. I'm assuming the card has some kind of error on it that just can't be repaired. It's an "off-brand" card, so I wouldn't even know who to send it back to, to have the manufacturer/distributor look at it.
Anyone had similar problems? Any additional "tricks" you've used, when for some reason or other, you can't retrieve an image from a card?
|Sep 28, 2003, 11:51 AM||#2|
Join Date: Aug 2002
There are programs online that are made to recover pictures from problem cards (although that attempt to format may have lost the pics permanently). One such program is DIR (Digital Image Recovery) which you can find via Google.com as well as others.
If nothing's recoverable and you want to just reformat the card, use the formatting program(s) that came with your reader. I know (for instance) for smart media cards there's usually a dedicated program for your reader called SMPREP.
A word of warning though, if you have continual problems with one card, suggest you toss the card before it tosses a valuable picture.
|Sep 28, 2003, 12:02 PM||#3|
Join Date: Sep 2003
Thanks - I'll have to check into what "Digital Image Recovery" does that is different from running Scan Disk.
Yep, the pictures on that second card are now gone for good, but I think the card is junk as well. Neither my computer nor the camera will format it.
I agree with your other suggestion completely - after one problem, I'd consider the card suspect, and after two, I'd either format it and start all over again, or toss it. Even if I did get to reformat it, I don't think I'd ever trust it for an important image.
Hey, how many pictures do you guys try to get on a card? If it's too many, and anything goes "wrong", you can lose way too many images. I know I never really feel comfortable until I've gotten the images off the card and onto my PC, and even then I really want to get them on a CD before I'm "sure" they won't get lost.
|Sep 28, 2003, 12:08 PM||#4|
Join Date: Jun 2003
Location: Savannah, GA (USA)
FAT corruption is the problem that is most common, although you can also have bad sectors, etc.
FAT (File Allocation Tables) become corrupted for any number of reasons.
Sometimes corruption happens when the card wasn't formatted correctly to begin with, resulting in errors in the FAT (or bad sectors that were not properly identified). Other times, when writing to the media, the writes are incomplete (card removed before FAT completed updating due to caching)
Caching is when an operating system delays writes to the media. It's a sophisticated processs that is designed to speed up writes (by stacking them in memory, then flushing them periodically). Some Camera Operating Systems even use this technique.
I can remember using utilities around 20 years ago for early DOS versions to fix disk corruption problems. The FAT design used by digital cameras is very old design, and is not perfect. Controller circuitry can fail too.
Are improvements being made? Sure they are. Media is becoming more reliable, with lower error rates than were common in the past.
To minimize problems, here are some suggestions:
1. Make sure your battery is charged properly before any writes to memory cards (formats, erases, etc.)
2. Always format your media (memory cards) WITH THE CAMERA before each use. This insures that you are starting out with a fresh File Allocation Table. Sometimes, there are minor differences between the way a Memory Card is formatted at the factory, and the way a camera's operating system performs this process.
3. Never use your PC to perform any write operations to your Memory Cards (erases, formats, etc.). There can be differences in the way the PC operating system performs file operations on the media, compared to the camera. Also, a PC's operating system often delays writes to the media, so if the card is removed from a reader (or the camera unplugged too soon), the FAT can become corrupted.
4. Always wait a little while after performing formats and deletes, before powering off your camera, to make sure that the operating system has finished updating the FAT Tables on the memory cards (some cameras, like the F Series Minolta cameras even have a light to warn you that updates are still taking place. There is a warning in the Minolta manuals about this light).
In fact, corruption problems are so common because people don't realize that updates to the media are not complete, that some manufacturers (like Lexar), have actually started including a light in their Memory Cards (newer memory sticks have this feature), so that users can tell if the updates are finished or not.
Errors in transmission and software occur -- even if we're only talking about going from one internal component to another, for any number of reasons (components, software, external influences, etc.).
Sometimes, you never do find the exact cause of a problem -- especially if it's intermittent..
Here are some of the warnings from Minolta, from the F Series Manuals (other camera manufacturers probably have similiar warnings):
"Always format the memory card using the camera; never use a computer to format a card."
"Memory cards - SD Memory Cards and MultiMediaCards are manufactured with precision electronic components. The following may cause data loss or damage:
• Improper use of the card.
• Bending, dropping, or subjecting the card to impact.
• Heat, moisture, and direct sunlight.
• Static electrical discharge or electromagnetic fields near the card.
• Removing the card or interrupting the power supply while the camera or a computer is accessing the card (reading, writing, formatting, etc.).
• Touching the electrical contacts of the card with your fingers or metal objects.
• Using the card beyond its life. Purchasing a new card periodically may be necessary.
Minolta has no responsibility for any loss or damage to data. It is recommended that a copy of the card data be made."
|Sep 28, 2003, 12:20 PM||#5|
Join Date: Jun 2003
Location: Savannah, GA (USA)
I've now owned 7 different Digital Cameras, and I have NEVER had a corrupted memory card. But, I ALWAYS format a card WITH THE CAMERA before each use, and I NEVER use anything except for the camera to perform any write operations to the memory cards.
Anyway, here is a free image recovery program.
The web page is in German, but the installation will allow you to select English as the Language. I have it installed on my PC, but I've never needed to use it (knock on wood).
You will see a download link for "Digital Image Recovery: on the page. Here is the download link, if you want to access it directly, without trying to find it on the main page:
You memory card must appear to be a drive letter to your PC operating system, and the program lets you look for deleted files on any drive letter.
The download is compressed (.zip file), so you will need pkunzip.exe or winzip (or another utility capable of extracting the installation .exe file to install it. You can download an eval copy of winzip here:
Note: the install will let you choose english as a language. It's very simple to use (pick the drive letter from a list, and it will find and recover any files on the drive). I've played with it, but I've never really needed it.
|Sep 28, 2003, 12:22 PM||#6|
Join Date: Aug 2002
|Sep 28, 2003, 9:14 PM||#7|
Join Date: Mar 2003
Has anyone made a correlation between memory card type (MMC, SM, SD, Memory Stick, etc.) and this type of problem?
I have two SD memory cards I use with my camera that I have NEVER formatted. In both cases when the card was put in the camera for the first time it was immediately recognized by the camera.
When downloading to the PC, I use a card reader. I copy to a folder in the hard disk, then, when I am sure everything is OK (never had a bad file) I deleted them from the PC. No format, just delete all files in the card. This is a no-no in the recommendations above, yet my experience tells me otherwise.
I have been doing this since I got my camera last December and some 3,000 pictures later, not a single corrupted file or card.
File format SHOULD NOT (in theory) be a problem, no matter how old the FAT format is. Floppy disks still use the same old FAT16 system. Same as used by the memory cards. Also, the computer is able to recognize and use different formats. Latest versions of Windows (2000 and XP) do NTFS, CDFS, FAT16 and FAT32 and probably more.
|Sep 28, 2003, 11:03 PM||#8|
Join Date: Sep 2003
If I was a manufacturer, I'd say to only work on my product with other of my products. That may be why battery chargers made by one company are "supposed" to be used with batteries provided by the same company, and why the manufacturer of a digital camera would say to always format the card with their camera.
I don't buy it with the batteries, and while I suggest people use their camera to format their cards, or delete images from teh card, I can't think of any logical reason not to do it with a computer.
I've never had a problem doing just what you just posted - I like the idea of removing the card from the camera, putting it into my card reader, and from then on treating it just like an add-on external hard disk.
I don't have a clue why the one card that I had a problem with (Smart Media) had a problem because of the computer or the camera, but neither could "see" the missing images. My brother's card went bad when he used it with his camera - he doesn't even have a card reader. At any rate, I think his card went bad because it developed a problem - I'm thinking it was a defective card to begin with, but maybe he dropped it or something... I don't know.
I suppose if I was the manufacturer of a digital camera, I'd say the same thing, but then again, these memory cards are made for all kinds of different purposes. Cameras are just one of them. It doesn't seem reasonable that a decent computer and a decent card reader/writer shouldn't be able to format or delete files on a card.
Scan Disk should be able to fix almost any problem other than a card that's defective, but so should formatting the card in the camera.
I went looking on the "SanDisk" website for information about these problems - here's what I found:
CompactFlash - General
My card is corrupt. What's up?
- Card works in camera but not the reader
- Card shows corrupt characters
- Card shows used capacity but no files are on it
- Card locks camera up
- Card does not work in device while other compatible cards do
- Card can not be written to or erased
- Reader or adapter crashes when card is inserted but works fine with other cards
- Card show card error in camera
- Card says it needs to be formatted when inserted in device or reader
- Shows less available pictures than normal and no pictures on card
- Card shows bad sectors in scandisk
- Camera can not be turned off with card inserted
- Card shows wrong capacity when formatting
SanDisk products: CompactFlash, SmartMedia, MultiMediaCard, Secure Digital, Memory Stick
Operating systems: Any
Hardware platform: All PCs, Macs, Cameras, Jornadas, MP3 players, voice recorders, etc.
Taking pictures too fast so the camera cannot finish writing them before the next one is taken
Turning off the camera while it is still saving information
Removing the card while the camera is still saving data to it
Taking pictures with weak batteries
Large static charges to the card
Sitting the cards on or near strong magnetic sources
Removing the card from the reader while you have files that are on the card open
Removing the card from the reader while it is still copying files to the hard drive
On a Mac, removing the card without first trashing the icon
On NT, removing the card without first running safe swap
On ME and win 2000, removing the card without first stopping it.
File corruption is caused by many things and our memory cards are less susceptible than regular hard drives or other media with moving parts.
To recover the pictures you can try the following
1. File recovery software will work in some cases (query on the internet for file recovery)
2. Locate a disk recovery service in your area (Try DriveSavers on the web at www.drivesavers.com or by phone at 1-800-440-1904. You may also try a search on the internet for data or disk recovery.)
3. Run Scandisk against the card
SanDisk does not do file recovery.
To make the card usable again
Format the card in the device using it
Place the card in a reader
Right click on the drive letter
Full format with no label
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