If it's of any interest to anyone, you can check flash memory (and weed out the fakes) with the useful f3 command line application.
http://oss.digirati.com.br/f3/
Personally, my Mint repo version of f3 was quite old so I compiled from source. You'll need to have the dependencies libudev1, libudev-dev and libparted0-dev pre-installed. To compile,
make all and
make experimental should do the trick. Then add the 5 executables produced (f3probe, f3brew, f3fix, f3write, f3read) to somewhere on your executable path (after which you can delete the compile folder).
Although it will ignore existing files, it's better to test on empty devices.
To run,
sudo ./f3probe /dev/sdb1/ - this is much faster than f3read and f3write for larger devices as it samples intelligently based on known fake flash techniques. If it finds problems, it will advise which f3fix command can be issued to resolve the issues.
If you want to check the whole drive:
./f3write /media/michel/5EBD-5C80/
./f3read /media/michel/5EBD-5C80/
It's best to remove and re-insert the device between f3write and f3read in order to flush the device's cache.
