USB stick leaking

"J. P. Gilliver (John)" wrote in message
...
[]
"Linea Recta" schreef in bericht
news I used a Lexar USB stick yesterday to boot a computer. I haven't used
the stick intensively, but now I noticed that it is leaking sticky
stuff from the seam on the sides. Any idea what the stuff is? Is it
toxic? Can I keep using the stick normally?
[]
An AMAZING amount of analysis from everybody!

Since nobody seems to think it _really_ is coming out (or at least no-one
can think of anything there'd be enough of to be oozing as described),
could it be that you - or someone in your household - has dropped it in
something, or dropped something on it (possibly from something leaking
above it), such that it just _looks_ as if it's coming out?

Is it data leaking out of the drive? Has the "sticky bit" been set? :-)

VanguardLH wrote:
Linea Recta wrote:

"VanguardLH" schreef in bericht
...
Linea Recta wrote:

"Linea Recta" ...

I used a Lexar USB stick yesterday to boot a computer. I haven't used
the stick intensively, but now I noticed that it is leaking sticky
stuff from the seam on the sides. Any idea what the stuff is? Is it
toxic? Can I keep using the stick normally?
The stick looks like this one:

https://www.amazon.com/Lexar-JumpDri.../dp/B0021AFWL4

but I took a magnifying glass to read what's exactly on mine:

lexar LJDTT4GB-000-1001AC
333074GBGA
N12610

product of China
http://www.lexar.com/products/usb-fl...ash-Drive.html

Those are not listed as waterproof/resistant so there should be no
silicone filling to ooze out (but shouldn't anyway since, when it set,
silicone is not going to ooze but burn from an overheated chip).

Is what oozed out soft or hard? Is it like paste that you can smoosh
between your fingers, like toothpaste? Is it rubbery, like silicone
caulking? It is hard, like the plastic shell itself?
It is sticky and quite soft. Colour: transparent yellowish.
I tried to clean it, but it seems the red colour of the case comes off
now...
BTW I'm not aware the stick ran hot.

"transparent yellowish" had me first think it was solder rosin (aka
resin aka flux); however, the chips, connector, and other components are
wave soldered onto the PCB. If rosin were oozing out, I'd suspect
someone refurbished the device by, for example, replacing the memory
chip and they had to use a rework station that employed rosin to assist
in removing the chip, dewicking the solder off the chip, and later when
soldering the new chip onto the pads on the PCB. When using rosin, and
in a rework lab, there is usually a bath where the parts are dipped or
sprayed to remove the excess rosin. Another possibility is excessive
application of rosin during original manufacturer.

https://www.youtube.com/watch?v=CalydGKwEy8

That shows a guy removing a memory chip and noticed there was excessive
rosin left behind. Rosin doesn't flow at room temperature. That's why
it stays in the core of solder thread that incorporates solder inside of
it. It does flow when heated. Just because it doesn't feel hot to you
does not mean the chip(s) was not hot. All USB flash drives generate
heat. A plastic case has a slower transfer rate than metal. That means
a plastic cased USB flash drive will dissipate heat more slowly and it
also means you won't feel as much heat. A metal cased drive will feel
hotter to the touch than with the same PCB and components on it inside
of a plastic case.

The shell is typically 2 halves made of plastic that are snapped
together. Maybe the soft stuff was a sealant. I'm guessing rosin.
Original manufacture would leave almost no rosin behind. Little, if
any, would be used during original manufacture and if any were used then
the PCB goes through a bath to remove the rosin. Maybe you got a
remanufactured device. Refurbished usually means just testing and
passing the device on if testing is successful. Most times, refurbish
has nothing physically done to the device. Remanufacture means
rebuilding some of it.

I don't have any of those so I cannot pop one apart to look inside.
Haven't found a Youtube video about USB drive disassembly that looks at
that specific brand and model. The above video is for a Lexar JumpDrive
but a different model. The video author noticed excess rosin on the
memory chip at timemark 5:50. He uses a hot air desoldering station
which does not apply any flux. What he noted on the memory chip was
already there. The flux was on the underside of the chip (between chip
and PCB). So the manufacture process used flux (rosin) but did not do a
good job at washing it off. It is a tight fit between chip and board
but the flux was all over the bottomside of the chip. Seems Lexar's
manufacture process is sloppy with rosin since it only needs to be
applied for soldering the pins on the chip and nowhere as much on the
pins as what is shown sticking to the bottomside of this chip in this
video. Sloppy manufacture.

There is a video here from a Kingston USB flash plant.

https://www.youtube.com/watch?v=PFEYLFhKNUM

What impresses me most, is the degree of robotic handling.

All except the last step, where sticky labels are being
applied by hand! A win for humans.

So maybe the yellow substance, is grease that fell off one
of the machines :-\

In the video, you can see the milling machine that scribes
the product into individual flash drives. It's a kind of
plunge router.

I expected all the handling after scribing, to be done by humans,
but nope, a win for the robots instead. The humans just
stand around and give interviews.

Paul

On 4/22/2017 5:18 PM, Paul wrote:
VanguardLH wrote:
Linea Recta wrote:

"VanguardLH" schreef in bericht
...
Linea Recta wrote:

"Linea Recta" ...

I used a Lexar USB stick yesterday to boot a computer. I haven't used
the stick intensively, but now I noticed that it is leaking sticky
stuff from the seam on the sides. Any idea what the stuff is? Is it
toxic? Can I keep using the stick normally?
The stick looks like this one:

https://www.amazon.com/Lexar-JumpDri.../dp/B0021AFWL4


but I took a magnifying glass to read what's exactly on mine:

lexar LJDTT4GB-000-1001AC
333074GBGA
N12610

product of China
http://www.lexar.com/products/usb-fl...ash-Drive.html


Those are not listed as waterproof/resistant so there should be no
silicone filling to ooze out (but shouldn't anyway since, when it set,
silicone is not going to ooze but burn from an overheated chip).

Is what oozed out soft or hard? Is it like paste that you can smoosh
between your fingers, like toothpaste? Is it rubbery, like silicone
caulking? It is hard, like the plastic shell itself?
It is sticky and quite soft. Colour: transparent yellowish.
I tried to clean it, but it seems the red colour of the case comes
off now...
BTW I'm not aware the stick ran hot.

"transparent yellowish" had me first think it was solder rosin (aka
resin aka flux); however, the chips, connector, and other components are
wave soldered onto the PCB. If rosin were oozing out, I'd suspect
someone refurbished the device by, for example, replacing the memory
chip and they had to use a rework station that employed rosin to assist
in removing the chip, dewicking the solder off the chip, and later when
soldering the new chip onto the pads on the PCB. When using rosin, and
in a rework lab, there is usually a bath where the parts are dipped or
sprayed to remove the excess rosin. Another possibility is excessive
application of rosin during original manufacturer.

https://www.youtube.com/watch?v=CalydGKwEy8

That shows a guy removing a memory chip and noticed there was excessive
rosin left behind. Rosin doesn't flow at room temperature. That's why
it stays in the core of solder thread that incorporates solder inside of
it. It does flow when heated. Just because it doesn't feel hot to you
does not mean the chip(s) was not hot. All USB flash drives generate
heat. A plastic case has a slower transfer rate than metal. That means
a plastic cased USB flash drive will dissipate heat more slowly and it
also means you won't feel as much heat. A metal cased drive will feel
hotter to the touch than with the same PCB and components on it inside
of a plastic case.

The shell is typically 2 halves made of plastic that are snapped
together. Maybe the soft stuff was a sealant. I'm guessing rosin.
Original manufacture would leave almost no rosin behind. Little, if
any, would be used during original manufacture and if any were used then
the PCB goes through a bath to remove the rosin. Maybe you got a
remanufactured device. Refurbished usually means just testing and
passing the device on if testing is successful. Most times, refurbish
has nothing physically done to the device. Remanufacture means
rebuilding some of it.

I don't have any of those so I cannot pop one apart to look inside.
Haven't found a Youtube video about USB drive disassembly that looks at
that specific brand and model. The above video is for a Lexar JumpDrive
but a different model. The video author noticed excess rosin on the
memory chip at timemark 5:50. He uses a hot air desoldering station
which does not apply any flux. What he noted on the memory chip was
already there. The flux was on the underside of the chip (between chip
and PCB). So the manufacture process used flux (rosin) but did not do a
good job at washing it off. It is a tight fit between chip and board
but the flux was all over the bottomside of the chip. Seems Lexar's
manufacture process is sloppy with rosin since it only needs to be
applied for soldering the pins on the chip and nowhere as much on the
pins as what is shown sticking to the bottomside of this chip in this
video. Sloppy manufacture.

There is a video here from a Kingston USB flash plant.

https://www.youtube.com/watch?v=PFEYLFhKNUM

What impresses me most, is the degree of robotic handling.

All except the last step, where sticky labels are being
applied by hand! A win for humans.

So maybe the yellow substance, is grease that fell off one
of the machines :-\

In the video, you can see the milling machine that scribes
the product into individual flash drives. It's a kind of
plunge router.

I expected all the handling after scribing, to be done by humans,
but nope, a win for the robots instead. The humans just
stand around and give interviews.

Paul


The complexity of these robotic machines is amazing, Designing and
building these machines must be an art in itself.

Rene

"J. P. Gilliver (John)" schreef in bericht
...
[]
"Linea Recta" schreef in bericht
news I used a Lexar USB stick yesterday to boot a computer. I haven't used
the stick intensively, but now I noticed that it is leaking sticky
stuff from the seam on the sides. Any idea what the stuff is? Is it
toxic? Can I keep using the stick normally?
[]
An AMAZING amount of analysis from everybody!

Since nobody seems to think it _really_ is coming out (or at least no-one
can think of anything there'd be enough of to be oozing as described),
could it be that you - or someone in your household - has dropped it in
something, or dropped something on it (possibly from something leaking
above it), such that it just _looks_ as if it's coming out?

[Does it smell or taste funny/good/bad? No responsibility taken if you
try, mind (-:!]
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

Sometimes you win, sometimes you learn.




This surely shows you don't know my household.



--


|\ /|
| \/ |@rk
\../
\/os

On 20/04/2017 18:45, VanguardLH wrote:
... Some use silicon to seal them. ...

That's silicone.

--

Brian Gregory (in the UK).
To email me please remove all the letter vee from my email address.

Brian Gregory wrote:
On 20/04/2017 18:45, VanguardLH wrote:
... Some use silicon to seal them. ...

That's silicone.


https://en.wikipedia.org/wiki/Silicone

"More precisely called polymerized siloxanes or polysiloxanes,
silicones consist of an inorganic silicon-oxygen backbone
chain (⋯-Si-O-Si-O-Si-O-⋯) with organic side groups attached
to the silicon atoms. These silicon atoms are tetravalent.

R R
| | R = methyl, ethyl, phenol
- Si - O - Si - O ... (presumably "making a different
| | stink while they cure")
R R

Silicone is sometimes mistakenly referred to as silicon. The
chemical element silicon is a crystalline metalloid widely used
in computers and other electronic equipment."

So they bear some vague relationship, by appearing
in the same Wikipedia article :-)

And the metalloid, I've not heard that term before. Apparently,
that's English for "we've having trouble categorizing the
properties of this material" :-)

https://en.wikipedia.org/wiki/Metalloid

Paul

Paul wrote:
And the metalloid, I've not heard that term before. Apparently,
that's English for "we've having trouble categorizing the
properties of this material"

The eternal war between the lumpers and the splitters :-)

Once upon a time, the table was metals and non-metals. Lumpers in
charge. Then along came some splitters dancing between the lines
https://en.wikipedia.org/wiki/Nonmet...cable_elements

The Talk section of the nonmetal article is fun, battling over the
metalloid controversies.

--
Mike Easter

Brian Gregory wrote:

VanguardLH wrote:

... Some use silicon to seal them. ...

That's silicone.

Keyboards often cannot keep up with my typing speed.
Sometimes my fingers don't do what I tell them to do.

On Mon, 24 Apr 2017 15:53:58 -0500, VanguardLH wrote:

Brian Gregory wrote:

VanguardLH wrote:

... Some use silicon to seal them. ...

That's silicone.

Keyboards often cannot keep up with my typing speed.


I'm the other way around. My typing speed can't keep up with my
keyboard. g


Sometimes my fingers don't do what I tell them to do.


My fingers *never* do what I tell them to do, whether I'm typing or
playing my guitar.


But leaving aside the issues with typing, I might have made the same
mistake you did. I never thought about the difference between silicon
and silicone before.

On Mon, 24 Apr 2017 16:59:50 -0700, Ken Blake
wrote:

On Mon, 24 Apr 2017 15:53:58 -0500, VanguardLH wrote:

Brian Gregory wrote:

VanguardLH wrote:

... Some use silicon to seal them. ...

That's silicone.

Keyboards often cannot keep up with my typing speed.


I'm the other way around. My typing speed can't keep up with my
keyboard. g


Sometimes my fingers don't do what I tell them to do.


My fingers *never* do what I tell them to do, whether I'm typing or
playing my guitar.


But leaving aside the issues with typing, I might have made the same
mistake you did. I never thought about the difference between silicon
and silicone before.

I've been aware of the difference for nearly all of my life, or at least
since I became aware of such a thing as breast implants. Silicone, yes,
but silicon would hang like a rock. No one wants that.

Besides, everyone has heard of "Silicon Valley" in northern California.
Silicone Valley would be completely different. Los Angeles, perhaps?

--

Char Jackson

Ken Blake wrote:

But leaving aside the issues with typing, I might have made the same
mistake you did. I never thought about the difference between silicon
and silicone before.

I know the difference. Just didn't manage to press long or deep enough
on the "e" key. I've done lots of home repair which includes
[re]sealing windows with caulking. That uses silicone. Silicon won't
squeeze out of a tube and it won't smooth out using a wet finger.

On Tue, 25 Apr 2017 00:26:18 -0500, Char Jackson
wrote:

Besides, everyone has heard of "Silicon Valley" in northern California.
Silicone Valley would be completely different. Los Angeles, perhaps?


LOL!

On Tue, 25 Apr 2017 02:49:18 -0500, VanguardLH wrote:

Ken Blake wrote:

But leaving aside the issues with typing, I might have made the same
mistake you did. I never thought about the difference between silicon
and silicone before.

I know the difference. Just didn't manage to press long or deep enough
on the "e" key. I've done lots of home repair which includes
[re]sealing windows with caulking. That uses silicone. Silicon won't
squeeze out of a tube and it won't smooth out using a wet finger.

Maybe he wore out his E key. On my keyboard, the E label has
just about worn out. I have had keyboards where I completely wore out
the E label. Then, there are the keys that I use so infrequently that
they have dust on them.

Sincerely,

Gene Wirchenko

In message , Ken Blake
writes:
[]
But leaving aside the issues with typing, I might have made the same
mistake you did. I never thought about the difference between silicon
and silicone before.

Silicon - quite hard. Except for its use in the semiconductor industry,
I'm not aware of any use of the elemental form (more or less a metal,
except in the ultra-pure form used in semiconductors). We had a lump of
it in the school chemistry lab, I think - somewhere like that; although
an extremely common element, I don't _think_ most people will come
across it in its metallic form. It's compound with carbon is much used
in drilling, cutting, sharpening, etc., as it's extremely hard.

Silicone - a rubbery substance (does actually contain silicon atoms,
hence the name, along with other elements). Actually a family of such
substances. Often used as a sealant. Commonest use mentioned in the
media - breast implants.

Common mistakes: "silicone chip" for semiconductors; silicon for breast
implants (which would be very uncomfortable!).
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

To keep leaf vegetables clean and crisp, cook lightly, then plunge into iced
water (the vegetables, that is). - manual for a Russell Hobbs electric steamer

"J. P. Gilliver (John)" wrote:

Silicon - quite hard. Except for its use in the semiconductor industry,
I'm not aware of any use of the elemental form (more or less a metal,
except in the ultra-pure form used in semiconductors). We had a lump of
it in the school chemistry lab, I think - somewhere like that; although
an extremely common element, I don't _think_ most people will come
across it in its metallic form. It's compound with carbon is much used
in drilling, cutting, sharpening, etc., as it's extremely hard.

Silicone - a rubbery substance (does actually contain silicon atoms,
hence the name, along with other elements). Actually a family of such
substances. Often used as a sealant. Commonest use mentioned in the
media - breast implants.

Common mistakes: "silicone chip" for semiconductors; silicon for breast
implants (which would be very uncomfortable!).

The alchemists never perfected turning lead into gold. However, with
technology, we managed to turn sand (silicon dioxide) into gold.

http://www.dowcorning.com/content/di...facturing.aspx
Now you all know why silicon and silicone are very similarly spelled.
There's no silicone without silicon.