verb13...
Just as a prelude to my add'l comments below...
For the past four years or so we have continually encountered 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. It's been a most frustrating
experience for many of us.
Anyway, 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...
(I fully recognize that not all the following will apply in your specific
situation or you've already tried some of these possible "fixes" without
resolving your problem, but I thought I'd list all of them for others who
may also be experiencing a problem in this area).
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. Again, if the problem device is a USB external HDD that is not being
recognized by the system - access the BIOS and disable the "boot from USB
device" option should that setting be present in the BIOS. Ditto for "USB
legacy support" or similar setting if present.
8. Try alternate powering ON/OFF methods. If the USB device contains its own
power supply (as in the case of a USBEHD), try booting up with the device's
power on, and if the USBEHD is not detected, then try powering on the device
only *after* the system has booted to a Desktop.
9. Try a different USB cable.
10. In the USB controllers section of Device Manager, uninstall all the USB
controllers listed and reboot.
11. If the device in question is not a commercial USB external HDD but
rather one in which you installed the (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 has never seemed to matter
how a USB external HDD (regardless of make/model) is jumpered when installed
as a USB device in an external enclosure. But I continue to see user reports
that a jumper change resolved the problem so it may be worth a try.
12. 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 disk.
13. And, of course, if you're able to uninstall the HDD from its enclosure
and have another HDD at your disposal, install the latter in the enclosure
and try that.
14. If the USB device is connected to a USB 2.0 PCI card, try changing the
card's PCI slot on the motherboard.
15. Access the website of the manufacturer of the USB device to determineif
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.
16. Determine from the manufacturer of your motherboard whether there's a
BIOS upgrade (or other software download) affecting USB device recognition.
We have encountered a few - very few - older motherboards (about five or so
years old) that exhibit USB 2.0 connectivity problems, even though they're
presumably designed for USB 2.0 capability and the installed XP OS includes
SP1 or SP2. I'm assuming your PC contains a SP since there were definite XP
OS-related USB-connectivity problems prior to the SP1 update). In a number
of those cases involving a motherboard problem an additional USB 2.0 driver
was included with the MB or available from the motherboard's manufacturer..
Theoretically there should not have been any need to install an auxiliary
USB 2.0 driver, but we found this was the only way to ensure reliable USB
2.0 connectivity. Admittedly this was a rare situation with only a very few
motherboards and we haven't encountered this identical problem with
motherboards manufactured over the past five years or so.
In your particular case, assuming you haven't already done this, refer to
item 8. above re powering on-off methods.
Also, items 7 & 10.
Also, seehttp://
www.uwe-sieber.de/usbtrouble_e.htmlfor add'l
troubleshooting tips.
Anyway, if you're able to resolve this problem keep us informed of the
"fix".
Anna
