Groups > comp.sys.mac.hardware.storage > #1379

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

From	not@telling.you.invalid (Computer Nerd Kev)
Newsgroups	comp.sys.mac.hardware.storage, comp.sys.ibm.pc.hardware.storage
Subject	Re: Is it me or are there many unreliable USB flash drives?
Date	2016-10-24 21:54 +0000
Organization	Aioe.org NNTP Server
Message-ID	<nulvue$1thd$1@gioia.aioe.org> (permalink)
References	(10 earlier) <211020161746161588%nospam@nospam.invalid> <nuglb2$us$1@gioia.aioe.org> <231020162053440081%nospam@nospam.invalid> <nujpbk$au4$1@gioia.aioe.org> <231020162203572861%nospam@nospam.invalid>

Cross-posted to 2 groups.

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In comp.sys.ibm.pc.hardware.storage nospam <nospam@nospam.invalid> wrote:
> In article <nujpbk$au4$1@gioia.aioe.org>, Computer Nerd Kev
> <not@telling.you.invalid> wrote:
> 
>> > 
>> >> 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.
>> > 
>> > no.
>> 
>> Yes. If the 5V supply circuit was built separately for use by
>> the relatively high current USB devices, it's failure (in this
>> way) would not stop the computer operating. In some cases it
>> might (I won't spend the time spelling it out), but if no USB
>> devices are connected, it won't.
> 
> usb devices are not 'relatively high current'.
> 
> usb originally specified a maximum of 500ma. the usb charging spec can
> go to about 2a, and at 5v, is just 10w.

It is for a laptop with internal hardware designed to conserve power
consumption as much as possible for the longest possible battery
operation time.

>> >> A power-boosted USB hub with a faulty or incorrectly specified
>> >> mains adapter powering it could also be a culprit.
>> > 
>> > no hub was used.
>> 
>> Known now, yes.
> 
> it was known before.

OK, missed it. You did too based on your earlier reply to Ant.

>> >> > 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?
>> > 
>> > usb devices don't work that way.
>> 
>> OK, so the device can specify roughly the current it needs via
>> the USB protocol, which if you're lucky will be respected by the
>> computer hardware.
> 
> luck has absolutely *nothing* to do with it.
> 
> the usb spec *requires* that a usb peripheral device use *up* *to*
> 100ma and then negotiate higher current requirements, which the usb
> host can deny.
> 
> anything else is not compliant with the usb spec.

Some cheap designs aren't, that's the luck.

>> The current specification isn't accurate
>> enough to prevent damage though, for the reason shown above.
>> The current increase as voltage is increased isn't great enough
>> to trip the limiting.
> 
> no.

Again, YES. You're arguments aren't very convincing.

>> >> >> 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. 
>> > 
>> > broken joints don't get hot. they simply don't work.
>> 
>> Sometimes they simply form a high resistance. Look it up - dry
>> joints.
> 
> they're commonly called cold solder joints, and will cause a device to
> fail not get hot.

They're commonly called as many things as USB memory sticks are, just
look up their failure modes and you'll see that they can get hot. It's
the same as a power plug with corroded/tarnished contacts getting hot.

>> >> It is a less common failure, but it's also
>> >> uncommon to consume large quantities of memory sticks.
>> > 
>> > it's not uncommon at all. memory sticks are cheap enough to be
>> > considered disposable. sometimes they're even given away for free.
>> 
>> As I remember it, OP figures that he's bought good ones - hence
>> his confusion about the cause of the failure rate.
> 
> it wasn't due to heat.

Maybe not, but they were apparantly getting unusually hot - sounds
like a potential connection to me.

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Thread

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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