Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Flakey 8GB Flash Drive

This is slightly off topic but perhaps you will indulge me.
I have a cheap 8GB "no name" flash drive. It formats and seems to behave
properly. I copied 1.5 GB of photos onto the drive. Some of the .jpg are
readable, but some are not although they are readable on the harddrive.
I tried reformatting, etc, but same issue occurs.
I can't really trust the flash drive.
Any suggestions on how to remedy and verify?
Thank you.
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Default Flakey 8GB Flash Drive

John Keiser wrote:
This is slightly off topic but perhaps you will indulge me.
I have a cheap 8GB "no name" flash drive. It formats and seems to behave
properly. I copied 1.5 GB of photos onto the drive. Some of the .jpg are
readable, but some are not although they are readable on the harddrive.
I tried reformatting, etc, but same issue occurs.
I can't really trust the flash drive.
Any suggestions on how to remedy and verify?
Thank you.

probably a fake. Probably has a smaller chip than advertised.
Fill it up, eject it, reinsert and try to read all the files back.
Files verify after copy because the OS is caching the file and giving
you back the cache instead of what's actually on the drive.
Eject/reinsert causes a re-read of the actual drive.

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Default Flakey 8GB Flash Drive


In article ,
John Keiser wrote:

This is slightly off topic but perhaps you will indulge me.
I have a cheap 8GB "no name" flash drive. It formats and seems to behave
properly. I copied 1.5 GB of photos onto the drive. Some of the .jpg are
readable, but some are not although they are readable on the harddrive.
I tried reformatting, etc, but same issue occurs.
I can't really trust the flash drive.
Any suggestions on how to remedy and verify?
Thank you.


An unfortunately high percentage of "high-capacity" no-name flash
drives are bogus. They actually have smaller storage capacities, and
their controller chips have been deliberately programmed to report a
false capacity. Accesses to sectors falling beyond the device's
actual storage boundary will often "wrap around" in an unpredictable
fashion, overwriting existing sectors with new data. The result is
just as you have observed - corrupted files.

This sort of falsification is often not detected by an operating
system's normal formatting routine, since formatting doesn't require
writing to more than a very small fraction of the sectors in the
filesystem.

In order to detect such forgeries in a definitive way, it's necessary
to write a unique pattern to each individual sector (e.g. fill each
sector with its own sector number), then read back every sector and
see if it has the right unique pattern in it. An honest drive will
past this test; a dishonest one will fail, and you'll be able to see
which sector's data clobbered which other sector.

From the behavior you report, it sounds as if you may have a 1-gig
drive, relabelled and reprogrammed to appear as if it were an 8-gig
drive.

Such counterfeit drives are not uncommon on eBay and similar online
auction sites, at electronic flea-markets, and so forth. It's best to
buy high-capacity drives from reliable local sources, and then test
the drives to confirm their legitimacy - and if they fail, take 'em
back to the store and raise a stink.

Remember, "cheap" is often very expensive.

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Default Flakey 8GB Flash Drive

Fortunately, only a $15 experiment.
Any clever way to get 1GB to work reliably or it is just toast?

Thank you both for the good clues.




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Default Flakey 8GB Flash Drive

I believe I need to reprogram the controller chip [MXT6208A]. I see the
software utility to accomplish this for another species of controller.
Google finds a possible tool for this chip also but the site is in Chinese
and I'll need help from a Chinese friend to get further with that
experiment.
All for

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Default Flakey 8GB Flash Drive

On May 1, 11:20*pm, "John Keiser"
wrote:
This is slightly off topic but perhaps you will indulge me.
I have a cheap 8GB "no name" flash drive. *It formats and seems to behave
properly. *I copied 1.5 GB of photos onto the drive. *Some of the .jpg are
readable, but some are not although they are readable on the harddrive.
I tried reformatting, etc, but same issue occurs.
I can't really trust the flash drive.
Any suggestions on how to remedy and verify?
Thank you.
--
Remove -NOSPAM- to contact me.


Just wondering - are you perhaps using it with a USB hub? I've had
problems in the past with larger capacity sticks in hubs.
Particularly hubs that include a jack for external power and that I
tried to power from my PC's jack instead. The addition of external
power seemed to cure my problems.

On the other hand, I recently bought a PNY 8GB flash drive that I
couldn't get to behave correctly, no matter what. I e-mailed them and
they just sent me another one (that worked, for free.)

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Default Flakey 8GB Flash Drive

On Friday 02 May 2008 14:20, Roger Blake wrote:
This kind of fraud is pretty typical of cheap Chinese products. If
the deal is too good to be true it usually is not true! I was reminded
of this recently when buying a nice-looking no-name universal remote
control for $2.00 at a local dollar emporium. After struggling to get
the thing working I opened it up and found a flimsy blank circuit board
with just a few components designed to make an LED blink when you touch
a button -- the whole thing was a fake, and was probably meant to sell
at a higher price.


My sister bought a universal remote control for just about that price, and it
worked...
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Default Flakey 8GB Flash Drive



"Wiebe Cazemier" wrote in message
.home.nl...
On Friday 02 May 2008 14:20, Roger Blake wrote:
This kind of fraud is pretty typical of cheap Chinese products. If
the deal is too good to be true it usually is not true! I was reminded
of this recently when buying a nice-looking no-name universal remote
control for $2.00 at a local dollar emporium. After struggling to get
the thing working I opened it up and found a flimsy blank circuit board
with just a few components designed to make an LED blink when you touch
a button -- the whole thing was a fake, and was probably meant to sell
at a higher price.


My sister bought a universal remote control for just about that price, and
it
worked...


You know, with today's technology, it really wouldn't cost much more to
build a real functional remote than to make a fake one that blinked an LED.
Microcontrollers are under a buck and most are far more powerful than needed
for that application.


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Default Flakey 8GB Flash Drive

Why don't you just toss it and buy a new one?

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