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Forum: Pentax DSLR Discussion
06-01-2010, 01:03 PM
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@sterretje thanks for the info. I already know deep in my soul that:
1) I'll never reproduce the problem
2) The "bad" card will continue to work for years in my netbook.
3) The camera will work fine forever.
This is why I believe their is a God and he hates me. (or has a sense of humor that no one else gets but him)
But on the plus side, I learned more about SD cards.
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Forum: Pentax DSLR Discussion
06-01-2010, 08:54 AM
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I think/hope its the card too. But I won't feel good until I can replicate it in a controlled way. I'll try to do some more testing. Since the badblock tests are all passing I'll try heating it up then testing. The camera had been on for about 3 hours. (not sure it would get hot enough to break solder joints or if the SD card even has solder) but I want to figure this out. I'll also take another 300+ pictures of my office to see if I can't get it to die again.
How complex are the controllers on SD cards. I know the controllers on SSD drives can do a lot of "magic". In other words your don't read from the memory locations directly on an SSD device. Everything is managed (or "faked") by the controller. Is that the same on the SD cards? In which case it would just take one mistake at the controller to think everything is 0x00.
btw, you can directly hexedit the SD card using /dev/mmcblkX in linux. But I have a dd dump too.
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Forum: Pentax DSLR Discussion
05-31-2010, 08:20 AM
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This is strange...
I've ran several destructive badblock checks against the card and it passes every time. (destructive meaning it writes/reads 0xaa then 0x55, then 0xff, then 0x00) I also verified the K-7 format function does not zero out the whole card. So now I'm left with no idea why the card works fine now. Nor do I know what caused the card to be zeroed out instantly.
What would cause an SD card to instantly become 0x00?
Would an ESD cause all 0x00 or would it be "random", or just broken?
Would an EMP cause all 0x00?
Any chance using Lithium batteries with the flash/or bad wiring in the flash cause a strong enough EMP to mess with the SD card? Any way to test? (If I do find an EMF meter to test it does anyone know what the normal magnetic field values should be?)
It was raining when it happened. I don't recall any thunder.
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Forum: Pentax DSLR Discussion
05-30-2010, 06:10 PM
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I pulled it up with a hexeditor and after just a few bytes of mostly partition information the card is ALL zeros. (No chance of recovering the photos) I'm now going to run a lot of badblock checks on it. I need to figure out if it was the card or camera (or both).
Does anyone know if the Pentax format function just wipes the partition and FAT table, or does it zero out the disk?
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Forum: Pentax DSLR Discussion
05-30-2010, 04:29 PM
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Thanks for the quick replies. I hope it's just the SD card, and not the camera. I tried two different recovery tools but they didn't work. I am now doing a low level disk dump of the card on my Linux box. Maybe I'll hack at the image with a Hex editor later.
I am upgrading the camera firmware, and I will use a new SD card brand. But it doesn't look like any of the firmware updates address this issue. (There is always the chance they found a bug and fixed it without announcing it) But even with the new firmware and a new SD card I'm still pissed and won't trust the camera because I'm not sure why it happened. God I'm pissed. I want Pentax (camera) or Centron (SD Card) to contact all the guests at the baby shower and apologize for me.
It appears that the camera will create the DCIM directory (maybe format too) if the SD card is new. I'm guessing the SD Card had some sort of IO error and Pentax didn't handle it properly. That is rather than just say, nope sorry, go away, the camera thought... must be a new card.. FORMAT!! I'm taking guesses here. Anyone have any more info? Can I take back all the nasty things I think about Pentax right now?
if ( i_dont_know_what_the_hell_the_card_says) {
format_card();
}
Would be better if...
if ( i_dont_know_what_the_hell_the_card_says ) {
if ( sd_card_is_all_zeros ) {
format_card();
else {
display_error();
prompt_user_for_option_to_format();
}
}
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Forum: Pentax DSLR Discussion
05-30-2010, 03:38 PM
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I just took about 300 photos on a 8GB SD card with my Pentax K-7. I had space for about 100 more. However, I tried to take another picture and the camera gave some error about not being able to save it. When I looked at the est number of photos left it didn't report anything. I turned off the camera, took out the SD card and put it back in. The camera reported space for 476 more photos. When I tried to preview the photos that should have been on the card it said "No image". When I got home I plugged the SD card into a computer. It showed the DCIM folder, but nothing in it. From my computer I created and deleted a folder in the DCIM directory to make sure the SD card could read/write.
Is there a way to recover data on the SD device?
Is there a firmware for the camera to fix this?
Is there an explanation why this happened?
If not, is there a way to get my money back for this camera and the lenses?
This is my 3rd SLR Pentax camera. I've used Pentax since I was 11 and have loved them. Please don't let this be the reason to stop recommending them.
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