How can I back up my files from a micro SD card when it keeps detaching itself?
August 21, 2011 3:42 PM   Subscribe

My micro SD card disappears intermittently, both from the smart phone its usually housed in (HTC incredible) and from computers (both Windows and Linux) when I try to read it (using one of these reader type things that plugs into a USB port). I want to back it up, but the card keeps vanishing as a drive when I try to do so. Any ideas about how I could copy the whole thing?

The phone gives a "SD Card Unexpectedly Detached" message (I'm enabling it to be read as a USB drive). When I remove the card and plug it into a computer's USB port, it copies for a bit, then just disappears as a drive. The computer gives some kind of "insert disk in drive E:" type message, acting as if there was nothing there. I'll pull it out and plug it in again, and it recognizes it as a drive, but it'll vanish again during copying.

It backs up *some* of the files during the copy operation, but it seems to bomb out sometime while it's in the middle of the images (of which there are about 1000).

What causes something like this? How could a file read operation trigger a card disconnect? Do I just need to suck it up and copy the files one by one to try to find the offending file? Or is there some other way to copy the whole card that won't trigger whatever it is that's causing it to disconnect itself?
posted by jasper411 to Technology (6 answers total) 1 user marked this as a favorite
It's probably related to heat or a cracked trace/broken connection. So try cooling the card before reading it (there's nothing in it you can hurt by freezing). Then try something like keeping light inward/downward/upward pressure on its tail while you read from it. It's a long shot but easy enough to try.
posted by introp at 3:53 PM on August 21, 2011

How about trying an app like LazyDroid (it's a 24 hour trial) that you can use your WiFi to pull things off. Same thing with WiFi File Explorer. Both give you an address to put in your Browser to pull things off.
posted by deezil at 3:56 PM on August 21, 2011

If I were given that card to back up, I'd be using Gnu ddrescue. It does a low-level block-for-block backup, keeping track of the blocks already successfully copied; it allows the operator to interrupt the copy process at any time, make whatever adjustments are needed (e.g. detaching and reattaching a failing drive) and resume the copy where it left off.

I'm also inclined to agree with the suggestion that cooling the card might help; it could well be that it's slight heating due to repeated access that's triggering the fault. Try putting the card in your USB reader, then putting that in a baggie and keeping it between two bags of frozen peas while doing the copy.
posted by flabdablet at 4:17 PM on August 21, 2011 [1 favorite]

Oops. Link to ddrescue.
posted by flabdablet at 4:18 PM on August 21, 2011

Do I just need to suck it up and copy the files one by one to try to find the offending file?

If you have a specific file or files on that card you don't have any other copies of, then try to copy them off and, if that fails, use GNU DDRescue as mentioned. There's more than one thing in the world called "ddrescue", and "GNU DDRescue" as linked to above is the one you want.

When you're done retrieving any data you may need, throw out the card and get a new one. Don't use known-unreliable media for anything, for any reason. That's just asking for pain.
posted by mhoye at 7:16 PM on August 21, 2011

Response by poster: These are all great suggestions, thanks so much. I'll try cooling it and see if that helps. Haven't had any luck getting the WiFi file explorer or lazydroid to work yet, I'm thinking maybe my antivirus software is blocking the port it uses, so I'll work on that. Definitely going to try that ddrescue, looks promising. And *definitely* I'm going to dump the card as soon as I can get the data off.
posted by jasper411 at 8:55 PM on August 21, 2011

« Older Raita/Indian Food Pairing   |   Cooking for one Newer »
This thread is closed to new comments.