USB device suddenly becomes "unknown device"


P

Pawel S.

hi guys,

today something strange happened to my 4port usb hub. after
soft-rebooting my system i wondered why my external drives and mouse
didn't work (all connected to my usb hub).
at closer look i found out that an "unknown device" is plugged into my
machine which happened to be the usb hub.

of course i tried unplugging and replugging it to other usb ports but no
effects at all - stll unknown.

so i googled and found out that some people have experienced similar
problems and solved it by uninstalling all usb devices from the device
manager, deleting an "infcache"-file and rebooting. (and yes, i did "set
devmgr_show_nonpresent_devices=1" and did remove the nonpresent devices).
no effect. windows boots, installs and detects all usb devices but the
hub still remains unknown.

the odd thing about that: it's not a hardware failure. the usb hub works
perfectly in knoppix or in the BIOS setup (tried it with an usb-keyboard).

furthermore all other usb devices do work on my usb ports and the usb
hub works great on other machines.

system recovery and safe mode have also no effects.

i'm really puzzled. any ideas?


regards
pawel

PS: i've also tried several chords.
 
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T

The Todal

Pawel S. said:
hi guys,

today something strange happened to my 4port usb hub. after soft-rebooting
my system i wondered why my external drives and mouse didn't work (all
connected to my usb hub).
at closer look i found out that an "unknown device" is plugged into my
machine which happened to be the usb hub.

of course i tried unplugging and replugging it to other usb ports but no
effects at all - stll unknown.

so i googled and found out that some people have experienced similar
problems and solved it by uninstalling all usb devices from the device
manager, deleting an "infcache"-file and rebooting. (and yes, i did "set
devmgr_show_nonpresent_devices=1" and did remove the nonpresent devices).
no effect. windows boots, installs and detects all usb devices but the hub
still remains unknown.

the odd thing about that: it's not a hardware failure. the usb hub works
perfectly in knoppix or in the BIOS setup (tried it with an usb-keyboard).

furthermore all other usb devices do work on my usb ports and the usb hub
works great on other machines.

system recovery and safe mode have also no effects.

i'm really puzzled. any ideas?

Try a different hub? I have a similar sort of problem with a USB2 cardbus
card on my notebook, which keeps showing as unidentified device and I have
come to the conclusion that it must have developed a fault.
 
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P

Pawel S.

Try a different hub? I have a similar sort of problem with a USB2 cardbus
card on my notebook, which keeps showing as unidentified device and I have
come to the conclusion that it must have developed a fault.

.... how could it have developed a fault if it still runs perfectly on
the same machine but on a different OS.

this looks clearly like a software issue to me.
 

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