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"USB Device not recognized"

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When my computer comes back from standby mode the following bubble error message pops up on my task bar even if there is NOT a device plugged into the USB port.

"USB Device not Recognized.

One of the USB devices attached to the computer has malfunctioned, and Windows does not recognize it.

USB Root Hub (2 ports)
? Unknown USB Device"

When the computer starts up from shutdown the USB devices I have (like a memory stick) will work fine. If however the computer goes into standby, when it comes back to active mode the USB drive will not read anything from the device that is still in the drive and will not recognize anything new.

When I check the status of the USB ports under the Hardware manager, it says that they are working properly. I have also tried to update the drivers but I get a message saying that no new driver can be found for the USB drive.

Any suggestions on how to fix this problem so that I don't have to continually restart my computer to get the USB ports to work? THANKS.
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    Je suis Napoléon!

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do you have usb ports on the front, the back, or both ends of your tower? if y ou have them in both places try using the opposite ones than the ones you normally use (usually use the front? try the back). i just had a similar problem with one of my machines here at work and it seems that the ports in the front are bad.
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I'm having this same problem with a laptop and my IntelliMouse Explorer mouse.

:tazz: I hope some people can help us!
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Thanks for the advice. My computer is actually a laptop with both USB ports being on the back.

Also, one more problem I forgot to add is that when the computer comes back from standby, the start menu and taskbar sometimes freeze up. I can access icons on the desktop and programs run fine, but the taskbar won't function and I can't get to anything off the start menu.
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Topic: USB Device not recognized

Date: July 19th – 2005

There are several issues/rules with USB that are not common knowledge:

1- Internal USB ports are current limited to 500 milliamps & a lot of
Power Supplies only have 2 –2 ½ amps of USB Power – The use of USB
HUB with an external supply is necessary for USB POWERED DEVICES –
such as ZIP Drives – Scanners – Memory Readers – Also many of these
HUBS have a – (EXT – INT ) Power Switch . . . TOTAL CURRENT of HUB
2- Use the internal USB Ports for USB devices that draw <260 ma & USE HUBS
(with external power supply) for the “Power Hogs” . . .The control lines from
the HUB to PC is < 4 ma demand on PC Power Supply
3- There are settings to be made in BIOS (1.1) – (2.0) or (1.1 & 2.0)
4- There is also a setting in BIOS about using Keyboard & Mouse for wake up
5- Also this feature requires a Power Supply that can provide 2 amps or more on the
+5VSB & requires a jumper to be connected & TOTAL CURRENT must not
6- There are 2 or 3 – USB Header Connector/Header that require jumpers
and wiring that are often wired wrong – loose – or not connected
7- Usually the Front USB ports (USB56) are not wired or are in error
8- The 2 or 4 USB ports that are near the Keyboard & Mouse Ports are hard
wired and are the most reliable – (USB12 or USB34).
9- Usually Drivers are installed 1st without hardware attached (to comply
with “Plug & Play” . . .Then turn off PC – Connect device – Turn PC On
and “New Device” will be found
10- Many drivers are not “Microsoft approved” – many work – few do not-
generally you can find a driver in driver section of PC that will work
11- Win – 98 drivers do not work; except on Win98 OS
12- Device Manager is good place to look 1st – You can even measure current
draw from the device
13- Some devices such as drives – Cameras – Memory Card Readers require
permission to disconnect before ejecting or just pulling the plug or turn off –
There will be a USB icon in Start Tray that you left click & all USB that need
permission will be listed - (Ones that are connected at the time) Left Click this icon & then left click the device in menu & you will get a message of:
(Yea or Nay) about disconnecting device.
14- If you have a ZIP drive – it is best to have an icon on desktop to right click & to
left click “EJECT”- (on drop down/up menu)- to eject a disk. Otherwise if you use the disk eject button – Zip drive may not be recognized & SYSTEM RESTART will be required
15- Same with using a Memory Reader Card/chip – DO NOT PULL CARD OUT of
slot, before having permission to do so – and don’t turn Camera off or disconnect without permission

To Original Poster – (redgreti) – Several issues apply here –

Are you using a HUB with external supply . . .and is supply connected properly –
(both AC-Power & DC-Power) & if there is a Selector Switch – Is it set to “Ext”.

These devices will draw the 500 ma & I suggest using a HUB for it, with external power supply.

Also your driver may be an issue . . .may not be Microsoft approved . . . That is probably the case if it does this every time you remove a chip . . .

The problem of going into standby & loosing control when coming back to the active state could be related to driver.

When you do restart system . . . .does the device work ok or do you have to shut down – remove USB cable – Power back ON & then reconnect USB Cable??

Do you have a USB Keyboard and/or USB Mouse? What activates/ brings system from Standby to Active? A USB device? such as mouse or keyboard?

What is probably happening is: You are shutting down the USB device & then you are turning power back on . . .you are probably causing a power spike & losing control of the driver...your system still sees driver but the device never got connected.

When you power up PC you load drivers 1st & then look for device . . .But coming out of standby. . . PC looses driver control of this device & when it looks for driver its gone & you cannot convince your PC that is there . . .

Try removing USB cable while in Standby . . . .Bring out of Standby & then reconnect USB cable . . .this may reduce the effect of the power spike. . .Maybe!

It also could be related to a wiring problem if using front ports.. . . There are 3 ground wires in the wire cable – only 2 are used . . .may have wrong one connected so the suggestion from: dsenette may have some merit. . . hence shedding some light on that problem. . . .

It could be related to USB Wake UP Feature if you are not meeting the 2 amp minimum requirement. How many USB devices do you have?

Please List. .&. .Try the standby – remove USB – Activate & see if USB Memory stick is OK

To darqblue: Not familiar with Laptops . . .Is your mouse USB try removing while in standby without activating . . . of course you may not be able to activate without a mouse...can you use a keystroke?


Edited by Jack123, 19 July 2005 - 03:03 PM.

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