Re: Flash drives destroyed?

On 12/25/2021 10:20 AM, micky wrote:
> In alt.comp.hardware, on Sat, 25 Dec 2021 09:59:08 -0500, micky
> <[email protected]> wrote:
> 
>> Flash drives destroyed?
> 
> I finally got the MP3 player to come alive, but question 1 below is
> still pending:
> 
>> 1) I was making a Macrium rescue USB from a new USB and it didn't work
>> the first time. I think it didn't finish.  So I ran it again and it
>> finished acc. to the PC, but it would no longer show a file list.
>> Windows sees me plug it in but Properties says the amount of free space
>> is zero and the amount of used space is zero.   Is it unusual for a new
>> usb drive to fail like this?
>>
>> 2) Then yesterday I was trying to get an MP3 player to play through the
>> AUX port of my car radio.  The album cover showed in the screen and the
>> play clock was ticking away, but no sound was coming out of the radio**,
>> except a little click when I unplugged the MP3 player.
>>
>>   But an hour later, the 400 songs I had added last year to the player
>> and which I had seen in file manager the day before could not be found.
> 
> Sorry about this line.  It turns out the MP3p player has two listings in
> File Manager, one for the SD card that fits in it.  I should have
> noticed this the first time, or at least the second time.   That's where
> all the songs are.
> 
>> Only the one song that came with it new.  Now today, plugging it in
>> doesn't display anything on the screen about its charging or
>> transferring, and pushing the On button does nothing even though it was
>> fully charged yesterdaay and I was careful to turn it off.
>>   Is this kind of failure unusual?
>>   It's AGPTek.  Is that a brand to avoid?
> 
> I guess it didn't fail completely, but I plugged it in two cables a
> total of 4 times and the screen never showed messages like it did two
> days ago.   And I pressed On a half dozen times with nothing happening.
> Finally I held it down 10 seconds, but it used to take one second
> 
> 
> I still need help with this:
>> **This is the 2nd mp3 player that seems to play based on the screen but
>> no sound comes out of the radio. It's possible there is a problem with
>> the Carkit attachment to the radio, but is there some way to plug an MP3
>> player into the mike jack of a PC and see if it plays there.  AFAICt,
>> you need special software like Voicemeeter?
> 
> 
> 
> Never mind:
>> 3) While I'm here, I have a Sandisk Clip, the smallest one they made,
>> and it to
> 

An MP3 player that offers an analog output, that cable should work
in any 1/8" jack, including the PC jack. The amplitude is probably 1V RMS,
which is "Line In" level.

Lithium batteries come in a couple types. LiCo has slightly fewer charge
cycles than LiFePO4 (iron phosphate), but LiCo hold twice as many WattHours.
The iron phosphate batteries are slightly more resistant to overcharge, which
is why they are used in backyard solar-powered lights. The battery charges during
the day, and the charging circuit lacks sophistication and the battery in the
thing "has to eat it". They can theoretically be charged 6000-7000 times
with a proper charger (Tesla Model 3 in China use iron phosphate, and apparently
models in the US will receive these too at some point - the car will lack a little
acceleration if iron phosphate is used in the car).

If the device was old enough to use Nickel Cadmium, it would have spewed
electrolyte all over the place while aging, and the corrosion would
ruin the electronics. For example, in pinball machines, the high score
used to be stored with nickel cadmium cells for power, and when the
cells leaked, the pinball main board would get damaged. And hobbyists
repairing these, have lots of fun repairing such damage. The reason NiCd
spew like that, is there is no intelligent charger to charge them. Li has
an intelligent charger.

They make various USB volts/amps meters for in-line measurement
of USB. You can use that to check your MP3 player while it is charging,
and see if the current draw is consistent with charging at C/2 or C/10
(fast charge or slow charge). Looking at the photographs of these
will tell you whether the firmware was ever finished in development.
I don't think I'd buy this one, but continue looking for a similar one.

https://www.amazon.ca/USB-Meter-Tester-Voltage-Current-Battery-Power-Multimeter-Tester-Resistance/dp/B07D36ZW7Q

You don't need a lot of silly functions in those, like Milliwatts.
USB2 can source 5V @ 500mA and such a little meter can tell you
whether the downstream device is in-bounds for a high power device.
The 100mA level is for low power devices. Like my mouse used to report
it draws "98mA". Since the config table is in units of 2mA, they tried
to make it "one step less than the low power limit". And the mouse
doesn't actually draw 98mA and that is purely a class indicator. It
means my mouse should not ask for 500mA. And my mouse should work on
an unpowered USB hub (they can source 100mA).

As for the characteristics of Flash memory, those vary, but modern TLC
can sometimes fail in as little as a year of light usage. TLC tend to
come in 32GB (or 16GB if they buy chips that are only half-working). Some
of the smaller sticks, if you could still find them, they might be
MLC or (less likely) SLC. My OCZ Rally2, is supposed to have two
4GB chips inside it, which is most likely MLC.

And when USB devices fail, yes, it is hard to tell what is going on.
You can't tell whether some code on the PC ruined them, or they
died of internal mis-management. In the end, it's all magic smoke
and it's gone. That's all we know.

    Paul