I have a 64GB SD card that I can't write to. When I put the lock on, I can read it just fine. But when I unlock it, it won't even mount. Windows just chokes on it and I have to hard reset the machine. Linux gives an error when trying to mount. I even tried zeroing it out with dd in Linux, which acts like it's doing something, but dmesg reveals that it is failing (and the exact error message turns up exactly 1 result in google, which was no help, and a shorter version of the error message turns up 6 results, all of which are the actual kernel code). The fact that nothing happened is verified by switching the lock switch back on, and it mounts right up and still has 30 gigs of shite on it.

Anybody ever had this problem? Is there any way to just zap the shite out of the card and make it do something?

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Posted by ILikeLSUToo

Central, LA

Member since Jan 2008

18018 posts

Posted on 8/17/14 at 11:30 pm to Korkstand

Curious what the error message said. It's possible the controller chip is failing or there's corruption somewhere preventing the unlocked mode from working, or it could be something mechanically wrong with the actual unlock switch (it is just a tiny plastic piece activating a dip switch).

Also, would it happen to be a Kingston?

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Posted by Korkstand

Member since Nov 2003

28684 posts

Posted on 8/17/14 at 11:57 pm to ILikeLSUToo

quote:
Curious what the error message said.

The dmesg error is:

quote:
mmcblk0: retrying write for general error
mmcblk0: mmc_blk_err_check: general error sending status command, card status 0x80900

Several of these crop up any time anything tries to access the card... mount, dd, whatever.

Trying to mount via the file manager gives:

quote:
WARN: volume was not unmounted cleanly.
ERROR: fsync failed.

fsck says:

quote:
Logical sector size is zero.

quote:
It's possible the controller chip is failing

Very likely, I guess. It just seems weird that it mounts up and I can read the entire 30GB that is on it just fine, as long as it is switched to write-protect.

quote:
or there's corruption somewhere preventing the unlocked mode from working

I ran badblocks in Linux, and it found zero errors. Of course, I don't know exactly how most of these tools work.

quote:
Also, would it happen to be a Kingston?

Sandisk

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Posted by ILikeLSUToo

Central, LA

Member since Jan 2008

18018 posts

Posted on 8/18/14 at 12:36 am to Korkstand

quote:
Very likely, I guess. It just seems weird that it mounts up and I can read the entire 30GB that is on it just fine, as long as it is switched to write-protect.

That's the part that makes me think of the switch itself. It's primitive, small, sort of fragile. There's a scotch tape trick to permanently make the SD card writeable if the protect switch malfunctions, but I'd consider it a last resort since I believe you have to physically break the plastic switch off.

quote:
SanDisk

Ah, ok. Curious because there was a Kingston scandal some years ago regarding counterfeit and less reliable SD cards making their way into Kingston distributors inventory.

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