Anna
Mon Jun 02 11:12:10 PDT 2008
>>> On Sat, 31 May 2008 15:34:01 -0700, bdnihm
>>> <bdnihm@discussions.microsoft.com> wrote:
>>>> I have been trying to look up my freeagent ext drive to my dell
>>>> dimension B110.
>>>> no luck. thought it might be the drive, but it worked first time when i
>>>> plugged it into a different pc.
>>>> any suggestions?
>>>> Thanks
>> "PW" <paulremove_williamson858@removehotmail.com> wrote in message
>> news:1ks6449s444kbss1avo9k1su6i9gjfpu7g@4ax.com...
>>> I had a Maxtor Ext HD and it worked great for a time. Then, my PC
>>> wouldn't even recognize it. I tried multiple USB ports and decided to
>>> buy a FreeAgent drive. It has been working great. I gave the Maxtor
>>> one to my wife and she has been using it without a hitch on her PC.
>>> Got me!
>>>
>>> -pw
> Anna wrote:
>> bdnihm, Paul (and anyone else who might be interested...)
>> These USB non-recognition problems have been vexing all of us for some
>> time now. Hardly a day passes where queries similar to the above are
>> posted to this and other newsgroups dealing with XP issues.
>>
>> We've become increasingly convinced that the relatively large number of
>> problems in this area involving the non-recognition of USB devices that
>> we've all been experiencing is an indication that there is something
>> seriously flawed with respect to either the USB 2.0 specifications,
>> possibly involving quality control issues affecting the manufacturer of
>> these USB devices as well as supporting components such as motherboards
>> and other USB-related components. Then too, we've become increasingly
>> suspicious of the XP OS as it relates to its recognition of and
>> interaction with these USB 2.0 devices.
>>
>> We have encountered far too many unexplained problems affecting
>> detection/recognition of these devices and their erratic functioning not
>> to believe that something is seriously amiss in this area.
>>
>> We continually encounter situations where a USB 2.0 device - generally
>> involving a flash drive or USB external hard drive, will work perfectly
>> fine in one machine and not in another. And, in far too many cases, we're
>> unable to determine why this is so since we're unable to detect any
>> hardware/software problem in the balking machine that would cause this
>> non-recognition effect.
>>
>> We've put together a more-or-less checklist for troubleshooting these
>> rather common USB non-recognition problems that (hopefully) may be of
>> some value to users encountering this type of problem...
>>
>> 1. Access Disk Management and see if the USB device is listed. If so, and
>> there's no drive letter assigned, see if you can assign a drive letter to
>> the device.
>> 2. If the USB device is listed in Disk Management with an assigned drive
>> letter, right-click on its listing and select Explore from the submenu.
>> Hopefully, Windows Explorer will open and the device will be listed.
>> 3. Connect the USB device *directly* to a USB port on the computer, not
>> via a USB hub. Try different USB ports should your computer have multiple
>> ports.
>> 4. Avoid using a USB extension cable.
>> 5. Try connecting a USB device (that does not contain an auxiliary power
>> supply) to a USB port both before and after the boot operation.
>> 6. Where a USB (or Firewire) external HDD is involved, access Device
>> Manager, highlight the Disk drives listing and click on the Action menu
>> item and then the "Scan for hardware changes" sub-menu item. Do the same
>> in Disk Management > Action > Rescan disks.
>> 7. Try alternate powering on/off methods. If the USB device contains its
>> own power supply, try booting up with its power on, then try powering on
>> only *after* the system has booted to a Desktop.
>> 8. Try a different USB cable.
>> 9. In the USB controllers section of Device Manager, uninstall all the
>> USB controllers listed and reboot.
>> 10. If the device in question is not a commercial USB external HDD but
>> rather one in which you installed a PATA HDD in a USB enclosure, jumper
>> the HDD as Master (or Single if the HDD is a Western Digital disk). A
>> number of users have reported that jumper configuration corrected their
>> non-recognition problem. In my own experience it didn't seem to matter
>> how a USB external HDD was jumpered. But it may be worth a try.
>> 11. If the device in question is a USB external HDD, first check out the
>> HDD with the hard drive manufacturer's diagnostic utility. If it checks
>> out OK, and you can remove the HDD from its enclosure (without voiding
>> any applicable warranty), do so and install the HDD as an internal HDD to
>> determine if there are problems with the drive.
>> 12. If the USB device is connected to a USB 2.0 PCI card, try changing
>> the card's PCI slot.
>> 13. Access the website of the manufacturer of the USB device to determine
>> if there's any firmware update or info re the problem you're experiencing
>> or there's any possibility that the USB enclosure itself might be
>> defective.
>> 14. Determine from the manufacturer of your motherboard whether there's a
>> BIOS upgrade affecting USB device recognition.
>> Anna
>>
>> P.S.
>> A number of posters have reported they've found useful information re
>> troubleshooting USB devices on this site...
>>
http://www.uwe-sieber.de/usbtrouble_e.html
>>
>
> Since you deal with more of these things than us home users, you could
> stock up on a diagnostic aid. This might allow basic characterization
> of performance, such as error rate, on a suspect USB port.
>
>
http://www.passmark.com/products/usb2loopback.htm
>
> In the lab, engineers use $35K to $50K digital storage scopes, and
> software like this, to check eye diagrams for USB2. Not every small
> development firm, can do characterization of their end product, and
> perhaps they have to send out the product for compliance testing.
> I've used this same test technique in the past, and it's fun, because
> the scope does all the work :-)
>
>
http://www.testequity.com/products/1181/
>
> One of the early USB2 equipped motherboards, had a BIOS setting
> for "drive strength" for USB2. Motherboards since then, no longer
> have a setting like that. I'm not aware of anyone using the drive
> strength setting, as part of experimentation with non-functional
> USB devices. But it was interesting that it was provided for
> the first ones.
>
> There is a known problem with ICH5/ICH5R Southbridge and USB port
> failures. When they fail, all the USB ports fail at the same time.
> But it shouldn't take too long to figure it out, as even plugging
> in things like USB keyboards doesn't work. And everything in Device
> Manager looks normal, as it is just the physical layer that has
> failed. I'm not aware of other chipsets having a problem like that.
> For add-in cards, apparently some NEC chips have had port failures,
> presumably due to ESD.
>
> Paul
Paul:
Thanks. We're quite familiar with the Passmark device having used it a
number of times in the shops I worked in. Unfortunately in the specific type
of problem under discussion I didn't find it a practical diagnostic tool in
that situation although the device did serve a useful purpose in other kinds
of USB non-detection problems.
And I certainly haven't worked with the Tektronix software that you
mentioned.
As far as the chipsets go, again, related to this *specific* USB
non-recognition problem primarily involving USB flash drives & USB external
HDDs, we have been unable to find any direct relationship between this or
that chipset and the cause of the problem. Needless to say it's been a very
frustrating problem because of the absence of a cause-effect relationship in
too many cases (at least our inability to find such). Frankly my own
suspicions fall on the XP OS and poor quality control involving these USB
devices (or a combination of the two!), but it's only my suspicion based on
anecdotal evidence and in no way would I want it be interpreted as
definitive.
Anna
