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Groups > comp.sys.mac.hardware.storage > #1368

Re: Is it me or are there many unreliable USB flash drives?

Cross-posted to 2 groups.

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In comp.sys.ibm.pc.hardware.storage Rod Speed <rod.speed.aaa@gmail.com> wrote:
> Computer Nerd Kev <not@telling.you.invalid> wrote
>> nospam <nospam@nospam.invalid> wrote
>>> Computer Nerd Kev <not@telling.you.invalid> wrote
> 
>>>> There are USB voltage meters sold cheaply on Ebay to
>>>> show if the USB voltage from a computer is too high/low.
>>>> If the USB voltage was far too high, the extra energy
>>>> would cause excessive heating of the drive.
> 
>>> if the voltage was too high, not only would it not
>>> be usb compliant, but it would likely fry anything
>>> plugged into it, which is expecting a regulated 5v.
> 
>> I don't mean by design (although anything's possible
>> with Chinese knock-off stuff, if that's involved), I mean
>> due to a failure of the computer hardware.
> 
>> Now the 5V at the USB ports being high would often only make sense
>> if they were supplied by a separate line from the power supply.
> 
> They are in desktops. That's the whole point of the +5V standby line.

No it isn't. The 5V Standby line is to enable the motherboard
hardware to detect when the power switch is pressed, and on
many motherboards it is used to power additional functions
while the computer is off as well.

The Standby line was only specified to 10mA before the ATX 2.2
spec. and 2A afterwards. That means that an ATX 2.2 PSU could
only supply power for four USB 2 ports at 500mA maximum output,
or two USB 3 ports as 900mA maximum output. Before ATX 2.2 no
USB port could have been provided with remotely enough power
from a PSU meeting the 10mA 5V standby minimum requirement.

http://pinouts.ru/Power/atx_v2_pinout.shtml

I know some PCs supply power to USB devices when off (I find
this a pain), but it's not the case in many designs, and the
required use of the 5V standby line by the motherboard's
circuitry means that damaging voltage on this line will affect
the computer at the same time as the USB devices, leaving the
user with more to worry about than just their memory sticks
dying.

>> If the internal computer components and the USB ports were
>> both subjected to a failure of the 5V voltage regulation, it
>> would be very likely to destroy the computer without the
>> user having any time to worry about their USB accessories.
> 
> Depends on how much its out by. Certainly if its out by enough
> to see what normally stays at room temp get very hot when
> doing nothing with just the USB stick plugged in, doing nothing.

The maximum voltage ratings would probably only be known by the
memory stick IC manufacturers and their clients, however 5.5V
is a common design maximum. 5.25V is the maximum PSU output
under the ATX specification.

>> Most desktop PCs have standard power supplies that
>> provide the USB 5V from the same lines as everything else,
> 
> That is just plain wrong. Its usually supplied by the +5V standby
> line, so you can wake the system by moving the mouse etc.
> 
>> so it is unlikely that an over-voltage situation
>> would only affect the USB ports.
> 
> You have that completely backwards.
>
>> A laptop, however, may have a separate power supply circuit
>> for the USB 5V. If this failed, and supplied too high a voltage, it
>> may not sevierely affect the normal operation of the computer.
> 
> In fact laptops are more likely to have a
> separate +5V line for the same reason.
>
>> A power-boosted USB hub with a faulty or incorrectly
>> specified mains adapter powering it could also be a culprit.
> 
>>> the amount of current sourced is limited by
>>> what the device negotiates from the host.
> 
>> Current limiting only protects against an over-voltage situation
>> if the device requires more than the minimum current limit (500mA)
>> to be damaged. If an IC in the memory stick normally draws 20mA
>> at 5V, it may draw 28mA at 7V (this based on rough calculations:
>> 5V / 0.02A = 250R   7V / 250R = 0.028A, but it proves the point),
>> however the IC may only be rated to sustain 5.5V, so it may be
>> damaged while only consuming 28mA. The rest of the components
>> in the memory stick will also be drawing additional power, but
>> you see that the total power draw is not increased enough to
>> hit the 500mA maximum if the stick normally draws, say, 100mA?
> 
>>>> Another possibility, if you only ever use one USB port (or a group
>>>> of similarly affected ones) for testing these memory sticks, is
>>>> that a high resistance in the computer's USB socket is causing
>>>> the _socket_ to heat up, and the heat is being transferred
>>>> to the drives themselves via the USB connector. Here, not only
>>>> the heat, but also the coresponding reduced power to the memory
>>>> stick, may induce irrecoverable write errors or other failures.
> 
>>> unlikely.
> 
>> Such failures are known to occour due to strain on solder joints
>> causing them to break, or joints that weren't correctly soldered
>> in the first place. It is a less common failure, but it's also
>> uncommon to consume large quantities of memory sticks.
> 
> But doesn?t explain why all the sticks get hot. 

"a high resistance in the computer's USB socket is causing
the _socket_ to heat up, and the heat is being transferred
to the drives themselves via the USB connector."

The socket is the bit in the computer.

If the same socket/s are used, all the USB memory sticks drawing
the same, or similar, currents will get hotter than normal. They
will also receive less voltage than otherwise due to the voltage
drop over the resistance of the failed solder joint - which is
waht causes the heat.

-- 
__          __
#_ < |\| |< _#

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Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-17 16:03 -0500
  Re: Is it me or are there many unreliable USB flash drives? Mark Perkins <mark@none.invalid> - 2016-10-18 04:04 -0500
    Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-18 16:27 -0500
  Re: Is it me or are there many unreliable USB flash drives? Doc O'Leary  <droleary@2015usenet1.subsume.com> - 2016-10-18 15:23 +0000
    Re: Is it me or are there many unreliable USB flash drives? "Happy.Hobo" <Happy.Hobo@Spam.Invalid> - 2016-10-18 12:13 -0500
      Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-18 16:28 -0500
        Re: Is it me or are there many unreliable USB flash drives? "Happy.Hobo" <Happy.Hobo@Spam.Invalid> - 2016-10-19 00:15 -0500
          Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-19 17:40 -0500
            Re: Is it me or are there many unreliable USB flash drives? "Happy.Hobo" <Happy.Hobo@Spam.Invalid> - 2016-10-19 17:52 -0500
              Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-19 18:11 -0500
              Re: Is it me or are there many unreliable USB flash drives? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2016-10-20 04:19 +0000
    Re: Is it me or are there many unreliable USB flash drives? Your Name <YourName@YourISP.com> - 2016-10-19 09:13 +1300
      Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-18 21:15 +0000
        Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-18 16:51 -0500
          Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-18 17:52 -0400
            Re: Is it me or are there many unreliable USB flash drives? Doc O'Leary  <droleary@2015usenet1.subsume.com> - 2016-10-19 15:41 +0000
              Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-19 11:49 -0400
                Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-19 17:42 -0500
          Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-19 16:05 +1100
      Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-18 16:32 -0500
        Re: Is it me or are there many unreliable USB flash drives? Your Name <YourName@YourISP.com> - 2016-10-19 13:28 +1300
          Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-18 20:41 -0400
        Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-19 15:48 +1100
          Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-19 17:50 -0500
            Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-20 15:48 +1100
              Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-20 14:48 -0500
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-20 21:14 +0000
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-21 21:41 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-21 17:46 -0400
                Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-21 17:23 -0500
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-21 18:27 -0400
                Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-21 18:05 -0500
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-22 21:26 +0000
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-22 21:27 +0000
                Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-22 17:37 -0500
                Re: Is it me or are there many unreliable USB flash drives? Your Name <YourName@YourISP.com> - 2016-10-23 14:16 +1300
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-24 01:36 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-23 22:03 -0400
                Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-24 13:54 +1100
                Re: Is it me or are there many unreliable USB flash drives? Doc O'Leary  <droleary@2015usenet1.subsume.com> - 2016-10-24 15:52 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-24 21:01 -0400
                Re: Is it me or are there many unreliable USB flash drives? Doc O'Leary  <droleary@2015usenet1.subsume.com> - 2016-10-25 15:56 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-25 12:33 -0400
                Re: Is it me or are there many unreliable USB flash drives? Doc O'Leary  <droleary@2015usenet1.subsume.com> - 2016-10-26 17:34 +0000
                Re: Is it me or are there many unreliable USB flash drives? "Happy.Hobo" <Happy.Hobo@Spam.Invalid> - 2016-10-26 13:59 -0500
                Re: Is it me or are there many unreliable USB flash drives? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2016-10-27 00:13 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-26 23:19 -0400
                Re: Is it me or are there many unreliable USB flash drives? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2016-10-26 00:09 +0000
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-22 21:22 +0000
                Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-24 11:43 +1100
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-24 01:31 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-23 22:03 -0400
                Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-24 13:51 +1100
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-24 21:42 +0000
                Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-26 06:59 +1100
                Re: Is it me or are there many unreliable USB flash drives? "Happy.Hobo" <Happy.Hobo@Spam.Invalid> - 2016-10-23 23:52 -0500
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-23 20:53 -0400
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-24 01:49 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-23 22:03 -0400
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-24 21:54 +0000
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-24 21:01 -0400
                Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-24 23:00 -0500
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-25 00:10 -0400
                Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-24 23:11 -0500
                Re: Is it me or are there many unreliable USB flash drives? not@telling.you.invalid (Computer Nerd Kev) - 2016-10-25 21:14 +0000
                Re: Is it me or are there many unreliable USB flash drives? Your Name <YourName@YourISP.com> - 2016-10-21 13:50 +1300
                Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-20 21:32 -0400
                Re: Is it me or are there many unreliable USB flash drives? Lewis <g.kreme@gmail.com.dontsendmecopies> - 2016-10-21 08:53 +0000
                Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-22 10:05 +1100
                Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-22 10:03 +1100
            Re: Is it me or are there many unreliable USB flash drives? Jolly Roger <jollyroger@pobox.com> - 2016-10-20 15:30 +0000
              Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-20 15:02 -0500
                Re: Is it me or are there many unreliable USB flash drives? Jolly Roger <jollyroger@pobox.com> - 2016-10-20 20:08 +0000
  Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-19 05:09 +1100
    Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-18 16:48 -0500
      Re: Is it me or are there many unreliable USB flash drives? Your Name <YourName@YourISP.com> - 2016-10-19 13:32 +1300
        Re: Is it me or are there many unreliable USB flash drives? nospam <nospam@nospam.invalid> - 2016-10-18 20:41 -0400
      Re: Is it me or are there many unreliable USB flash drives? Jolly Roger <jollyroger@pobox.com> - 2016-10-19 00:38 +0000
        Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-18 21:30 -0500
          Re: Is it me or are there many unreliable USB flash drives? Jolly Roger <jollyroger@pobox.com> - 2016-10-19 15:50 +0000
            Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-20 05:01 +1100
        Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-19 16:08 +1100
      Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-19 16:02 +1100
        Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-19 18:10 -0500
          Re: Is it me or are there many unreliable USB flash drives? "Rod Speed" <rod.speed.aaa@gmail.com> - 2016-10-20 16:01 +1100
  Re: Is it me or are there many unreliable USB flash drives? Ed Light <nobody@nobody.there> - 2016-10-24 16:11 -0700
    Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-24 23:01 -0500
  Re: Is it me or are there many unreliable USB flash drives? Ed Light <nobody@nobody.there> - 2016-10-24 16:16 -0700
  Re: Is it me or are there many unreliable USB flash drives? Ed Light <nobody@nobody.there> - 2016-10-24 16:19 -0700
    Re: Is it me or are there many unreliable USB flash drives? ANTant@zimage.com (Ant) - 2016-10-24 23:02 -0500
      Re: Is it me or are there many unreliable USB flash drives? Ed Light <nobody@nobody.there> - 2016-10-24 21:38 -0700

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