Recover failed SD card

[Valeri Galtsev]

On 2/23/19 6:46 PM, @lbutlr wrote:
> On 23 Feb 2019, at 13:50, Bruce Ferrell <bferrell at baywinds.org> wrote:
>> Unfortunately flash memory "wears out".  There are spare storage blocks and logic to level wear by switching th the spares when main block failures are detected.
> 
> Yeah, that’s good theory, but it’s not what has happened with mine. Genrally they fail in the first few weeks. Even if it takes longer, it is not like they have been written and rewritten  many times. This isn’t a wear issue, it is an "SD Cards Break easily" issue.
> 

With all statements like that I would really like to hear at least the 
following about failed devices:

1. brand and model of device that failed on you

2. the source (vendor) you got the device from

The truth is that there is lot of garbage that is manufactured and sold, 
and flash cards are the ones that have really gross difference between 
good (proper) ones and bad ones. Finite number of write operations is in 
specifications od flash memory. Fatal failure after short use is not, 
and is an indication of garbage device. Another example in the same 
lines would be rechargeable batteries (specifically: 16340 LiPo were the 
ones I was getting for myself recently, and it took me quite some effort 
to pick the good ones - knocking on wood).

Now, I use and used in my car camera (read: written and overwritten all 
the time I drive), no failures:

1. High grade Samsung 128GB 100MB/s (U3) MicroSD EVO Select;

2. This one I do not consider the best, but it survived at least 6 years 
of use in car camera: Micro Center class 10 Micro SD (32 GB)


So, instead of generalizing, I would really like to hear the detailed 
information about _failed_ devises

Just my $0.02

Valeri

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Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
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