HELP: USB device keeps redisconnecting... woes :S

[KevinGPO]

Hi

Does anyone know why Windows XP would disconnect and reconnect USB devices
after long usage?

I have two USB devices which I was using for over 2 hours on my laptop.
Then, one at a time, one would have it's information reset. Then the 2nd
device resets when I reconfigure the 1st one. The only time the device
resets is when you pull out and reinsert the device in the USB socket.

Normally the USB devices work fine but why did the above problem happen?
Maybe Windows started disconnecting the USB devices because it ran out of
memory? Or maybe the laptop computer was overheating? (I usually have to
raise the laptop on sticks to allow ventilation on the bottom, but the time
it was frequently disconnecting my devices was when the laptop was on the
table for long period).

Specifications:
Toshiba Portege A100 - 0052E
Intel Pentium M 1.4GHz (Centrino Mobile Technology)
256MB DDR SDRAM
All 4 sockets are USB 2.0

So does anyone have any idea why Windows would do such a thing?

 

[R. McCarty]

Check the Power Management of the USB hubs. By default XP
sets the option "Allow Windows to turn off this device to save power".
Open Device Manager, expand Universal Serial Bus Devices.
Double-Click each Root Hub, Power (TAB) and check the option
box.

 

[KevinGPO]

Thanks. You mean uncheck/untick the box?

Check the Power Management of the USB hubs. By default XP
sets the option "Allow Windows to turn off this device to save power".
Open Device Manager, expand Universal Serial Bus Devices.
Double-Click each Root Hub, Power (TAB) and check the option
box.

 

[R. McCarty]

Yes I did mean uncheck/untic it, typing today without reading glasses.

 

[frankg]

i read this post with interest as i have a different but possibly related
problem - i have an external usb hard drive for backups - but the
'connection' and writing ability is intermittent. And I recently had a
backup disaster where the data wasnt written. Could it be that windows
switches it off after a time ??
===============================

 

[R. McCarty]

It's possible, but I'm not sure how the inactivity timer works with the
USB channels. I usually just globally turn off the power saving options
for hubs. I've got a Maxtor external and originally I had many issues
with transfers and data corruption. Turns out in my case that the disk
policy was set for enabling the Write Cache. Once I turned that off
the Maxtor hasn't had an issue since then. Even though USB-2 has a
speed rating of 480 Megabytes that's only a maximum. In reality, a
USB 2.0 external is only capable of around 25-28 Megabytes. So,
enabling the write behind caching isn't going to result in much higher
throughput. You'll find the Policy settings in the Disk Drive category.

 

[frankg]

my external usb HD has the write cache off , an the internal drive has it
on - i think that's good ?

 

[SeaMaid]

Heat could also be a problem, especially with 7200rpm external drives. Does
your external USB hard drive enclosure have any cooling fans?

 

[Quaoar]

It's possible, but I'm not sure how the inactivity timer works with
the USB channels. I usually just globally turn off the power saving
options for hubs. I've got a Maxtor external and originally I had
many issues with transfers and data corruption. Turns out in my case
that the disk policy was set for enabling the Write Cache. Once I
turned that off the Maxtor hasn't had an issue since then. Even
though USB-2 has a speed rating of 480 Megabytes that's only a
maximum. In reality, a USB 2.0 external is only capable of around
25-28 Megabytes. So,
enabling the write behind caching isn't going to result in much higher
throughput. You'll find the Policy settings in the Disk Drive
category.

I would first look at the power requirements of the drive. This is
exactly the behavior of a drive without sufficient power. The only
external drive I have used that will work with just USB power is a very
slow old laptop drive. Any newer drive requires external power.

Q