Windows not recognizing USB 2.0 external drive.

  • Thread starter Thread starter Doc
  • Start date Start date
D

Doc

Have a 250 gig Simpletech USB 2.0 external h/d.

I have 2 systems, one is running XP Home, one is running XP Media. On the XP
Home machine, I have a Techgear USB 2.0 card running and when I start the
drive, it recognizes and accesses it fine.

However, on the XP Media machine which has built-in USB 2.0 ports, I get a
"drive not recognized" message. Isn't XP supposed to have support for
external drives? Perhaps I need to adjust something?
 
However, on the XP Media machine which has built-in USB 2.0 ports, I get a
"drive not recognized" message. Isn't XP supposed to have support for
external drives? Perhaps I need to adjust something?
Click to expand...

I forgot to mention that it did successfully access it once, but on
subsequent attempts have had no success.
 
Might need to check "Full" Device Manager listing(s) with a couple
of System Variables and the "Show Hidden Devices" option enabled.
Would need to check for existence of "Other Devices" category and
"Unknown" device entries in the Universal Serial Bus Controllers category.

Possible the drives where misidentified or enumerated incorrectly.

Variables are:
DevMgr_Show_NonPresent_Devices
DevMgr_Show_Details
w/ both set to a value of 1
 
R. McCarty said:
Might need to check "Full" Device Manager listing(s) with a couple
of System Variables and the "Show Hidden Devices" option enabled.
Would need to check for existence of "Other Devices" category and
"Unknown" device entries in the Universal Serial Bus Controllers category.
Click to expand...

I had been plugging into the 2 ports on the front of the case, I've
since discovered that it works fine when plugged into one of the 4 2.0
ports on the back of the mobo. Interesting. Wonder why this is.

Do you think the suggestions you've made will have any effect on this?
While I've found a way to make it work, would be nice to be able to
plug in to the front.
 
If the device is a USB 2.0 it makes no difference which USB socket
you plug into. Only USB1(.1) devices have some correlation to the
socket used and how XP detects/maps them. USB1(.1) devices are
internally routed to one of several USB hubs. This is why if you plug
them into different sockets XP "Thinks" it's a new device and not an
existing instance of it. Using the instructions from the prior post you
may find "Phantom" device entries in Device Manager that may be
why when you re-plug them they do not work. ( XP recognizes them
from a prior hardware profile and doesn't try to reinstall them).
 
I had been plugging into the 2 ports on the front of the case, I've
since discovered that it works fine when plugged into one of the 4 2.0
ports on the back of the mobo. Interesting. Wonder why this is.

Do you think the suggestions you've made will have any effect on this?
While I've found a way to make it work, would be nice to be able to
plug in to the front.
Click to expand...

Check for dust bunnies in the ports....A couple of squirts using
a can of compressed air sometimes ends this problem.
 
(BASIC PROBLEM IS THAT OP'S USB EXTERNAL HARD DRIVE IS NOT DETECTED WHEN
CONNECTED TO FRONT PANEL USB PORTS, BUT NO DETECTION PROBLEM WHEN CONNECTED
TO USB REAR PANEL PORTS)


docsavage:
I trust I've correctly stated your problem in the lead-in to this posting.
Assuming that I have, and further assuming that when you say there's no
detection problem with your USB external device "when plugged into one of
the 4 2.0 ports on the back of the mobo", you mean there's no problem with
ANY of the rear panel USB ports...

If your problem still exists after you've tried R. McCarty's suggestions...

While the following may not be the root cause of your particular problem I
thought you might be interested to know that we've found many instances of
misconfigured/misconnected leads involving USB front panel ports.
Interestingly, this problem frequently occurred whether the desktop PC was
homebuilt or a commercially-built product. We've come across a number of
situations where there apparently was *no* attempt by the builder to connect
the front panel USB leads to the appropriate connector on the motherboard.
So it's something to check out especially in a case like yours where there's
no problem with rear panel USB ports.

I'm not sure how experienced you are in this particular area. Because of the
non-standardized (to a large extent) connection process re these front panel
USB leads, it sometimes becomes quite confusing as to which lead goes where.
Ideally you might know a knowledgeable friend who has some experience in
this area assuming you do not have this experience. Otherwise, a PC repair
shop may be an option. Of course, you can always live with non-functioning
USB front panel ports since you have other ports that are usable.
Anna
 
R. McCarty said:
If the device is a USB 2.0 it makes no difference which USB socket
you plug into. Only USB1(.1) devices have some correlation to the
socket used and how XP detects/maps them. USB1(.1) devices are
internally routed to one of several USB hubs. This is why if you plug
them into different sockets XP "Thinks" it's a new device and not an
existing instance of it. Using the instructions from the prior post you
may find "Phantom" device entries in Device Manager that may be
why when you re-plug them they do not work. ( XP recognizes them
from a prior hardware profile and doesn't try to reinstall them).
Click to expand...

This is not the modus operandi of the USB system. Unless a peripheral
contains a serial number, Windows will always treat it as a new device when
it plugged into a different port and installs another driver (after all, how
can Windows know that it is not a different dvice?). USB2 carries out this
process much quicker than USB1, so it may appear that it is immediately
accepted - if the driver is available. If the peripheral is serial
numbered, then Windows recognises it immediately and enumerates it with the
existing driver.

In the OP's case, it is possible that one of these reinstalls has failed for
some reason and the device is logged as an unknown device. There is also
the possibility that if it works on a rear mounted USB connector but not on
a front mounted connector, that the cable connecting the front panel
connectors to the motherboard is not quite up the task of carrying USB2
signals (flat cable?). If this is the case, then the error may have caused
the device to not be recognised.
 
Back
Top