USB 2.0 switch making scanner "unknown device"

D

Daniel

I recently purchased a USB 2.0 4-to-1 switch to share an "EPSON
Perfection 3200 Photo" scanner between 2 PCs: One running Windows XP
(WXP), the other running Windows 2000 (W2K).

When the scanner is connected through the switch to the WXP PC, the
scanner is recognized and everything work flawlessly on that PC.

However, when the scanner is connected through the switch to the W2K
PC, the scanner is not recognized and Device Manager reports it as
"Unknown device". This is despite the fact that when the scanner is
connected *directly* to that same W2K PC, it is recognized and
everything works well.

Any idea why? Aren't those USB switches supposed to be "transparent"?

Any tip how to solve this problem would be greatly appreciated.

Thanks,
Daniel
 
D

Daniel

Geoffw said:
install the win2K drivers for the device "EPSON Perfection
3200 Photo"
Click to expand...

Geoff, thanks for your reply but I already indicated that the "EPSON
Perfection 3200 Photo" scanner works perfectly when connected directly
- Which means the W2K drivers for it are already installed.

Nevertheless, I managed to solve the problem. I did so by by using
Control Panel's "Add/Remove Hardware" to remove the hidden "USB Human
Interface Device" *while* the scanner was connected directly.

Apparently, the order in which these USB devices are
connected/installed is critical to the sucessful working of this.
Thus, the scanner must be connected and all its drivers installed
*first* - and only then connect it via the switch.

All is well now. No additional drivers are necessary. :)

Daniel
 
D

Daniel

Unfortunately, I was to quick to celebrate :-(

What I stated before is absolutely correct, but only part of the
time... Depending on the "machine's mood" the PC would boot
recognizing the scanner via the switch, or would boot reporting
"Unknown device" as I reported in the original posting.

Unfortunately, the rate of unsuccessrul such boots is much greater
than the successful ones... :-(

I am still researching the problem. I will post an update once I track
it. On the face of it, this seems like a TIMING problem.

BTW, my PC is built around an ASUS P4P800 Deluxe motherboard /
P4-2.6CGHz overclocked to 3.12GHz. All latest drivers officially
released by ASUS are installed. The USB controller to which the
scanner/switch is connected is an "Intel 82801EB USB Universal Host
Controller" - Driver Version: 5.0.1006.0 from 1/15/2003. Could there
be a newer driver?


Daniel
 
V

Vance Green

Daniel said:
Unfortunately, I was to quick to celebrate :-(

What I stated before is absolutely correct, but only part of the
time... Depending on the "machine's mood" the PC would boot
recognizing the scanner via the switch, or would boot reporting
"Unknown device" as I reported in the original posting.

Unfortunately, the rate of unsuccessrul such boots is much greater
than the successful ones... :-(

I am still researching the problem. I will post an update once I track
it. On the face of it, this seems like a TIMING problem.

BTW, my PC is built around an ASUS P4P800 Deluxe motherboard /
P4-2.6CGHz overclocked to 3.12GHz.
Click to expand...

Stop overclocking and try again.

Your guess at it being a timing problem could
definitely be connected to OC.
 
D

Daniel

Vance Green said:
Stop overclocking and try again.

Your guess at it being a timing problem could
definitely be connected to OC.
Click to expand...

Just tried that - with the same results. :-(
It seems that overclocking is not the source of the problem - the
systems functions *perfectly* on all other respects while overclocked
20%. It even functions perfectly with the scanner connected directly
via the same USB port (as I previosuly mentioned).

Continuing the search...

Thanks,
Daniel
 
G

Geoffw

Daniel said:
"Geoffw" <[email protected]> wrote in message

Geoff, Thank you! I didn't know about this site. Certainly looks
promising. I will study it carefully - perhaps I can find there some
hints or even solutions.

Thanks,
Daniel
Click to expand...

hope you do

good luck

Geoff
 
G

Geoffw

glad that helped Daniel

yes it was a long process.

I have a similar problem with a removable usb2 hard drive
enclosure, but have already tried a couple of cables, maybe
I should get another :))

well done

Geoff
 

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