Discussion:
Malfunction of USB-ports
(too old to reply)
Klaus Haber
2008-11-28 10:24:27 UTC
Permalink
Hello,

I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.

I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances?
If I connect the scanner to the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board.

Is there one possibility to test generally an USB-port for its
functionallity?

Thank you for comments, regards

Klaus Haber
--
Homepage: http://www.bingo-ev.de/~Klaus.Haber
"pH-Messung - einfach zu verstehen"
neu: "Eine Hundegeschichte"
http://www.bingo-ev.de/~Klaus.Haber/akita.html
Rob
2008-11-28 13:13:35 UTC
Permalink
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances?
If I connect the scanner to the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board.
Is there one possibility to test generally an USB-port for its
functionallity?
Poor quality (or incorrect) case wiring to the front USB ports is probably
the cause, rather than a motherboard fault, as I have seen similar issues
with
many different systems.
Do you have any rear USB ports which plug into a different motherboard
header? If so, plug these into the suspect header instead of the case front
ports and try with your scanner. If it now works, you know the problem is
bad front case USB wiring and not a faulty mobo.

HTH,
--
Rob
Klaus Haber
2008-11-28 13:52:26 UTC
Permalink
Hello Rob,

thanks for reply!
Post by Rob
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances?
If I connect the scanner to the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board.
Is there one possibility to test generally an USB-port for its
functionallity?
Poor quality (or incorrect) case wiring to the front USB ports is probably
the cause, rather than a motherboard fault, as I have seen similar issues
with
many different systems.
Do you have any rear USB ports which plug into a different motherboard
header?
Sorry, english is not my motherlanguage and I did not understand the last
sentence well. What is a "motherboard header"? By the way, I habe no
different motherboard.
Post by Rob
If so, plug these into the suspect header instead of the case front
ports and try with your scanner. If it now works, you know the problem is
bad front case USB wiring and not a faulty mobo.
What I don't understand is, that other equipment will run at theese two
ports, only the scanner will not do so. That means in my eyes, that the
scanner is missing something which will not influence the other running
equipment. Perhaps a special signal, a voltage and so on. Is this possible?
USB connection ist a standard one and it is valid - as far as I know - for
all USB-users. And the fact, that other equipment will run creates in me
the opinion, that the port must be ok. But I am only a user and not a profi
;-)

Regards

Klaus
--
Homepage: http://www.bingo-ev.de/~Klaus.Haber
"pH-Messung - einfach zu verstehen"
neu: "Eine Hundegeschichte"
http://www.bingo-ev.de/~Klaus.Haber/akita.html
Rob
2008-11-28 14:36:32 UTC
Permalink
Hi Klaus,
Post by Klaus Haber
Hello Rob,
thanks for reply!
Post by Rob
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB
2.0-ports,
4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances?
If I connect the scanner to the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board.
Is there one possibility to test generally an USB-port for its
functionallity?
Poor quality (or incorrect) case wiring to the front USB ports is probably
the cause, rather than a motherboard fault, as I have seen similar issues
with
many different systems.
Do you have any rear USB ports which plug into a different motherboard
header?
Sorry, english is not my motherlanguage and I did not understand the last
sentence well. What is a "motherboard header"? By the way, I habe no
different motherboard.
It is a difficult thing to explain, even if english is your first language!
:)
Maybe this site will help:

http://www.directron.com/installusb.html

You will need to look at the 'onboard connectors' section of your
motherboard manual, too.
Post by Klaus Haber
Post by Rob
If so, plug these into the suspect header instead of the case front
ports and try with your scanner. If it now works, you know the problem is
bad front case USB wiring and not a faulty mobo.
What I don't understand is, that other equipment will run at theese two
ports, only the scanner will not do so. That means in my eyes, that the
scanner is missing something which will not influence the other running
equipment. Perhaps a special signal, a voltage and so on. Is this possible?
USB connection ist a standard one and it is valid - as far as I know - for
all USB-users. And the fact, that other equipment will run creates in me
the opinion, that the port must be ok. But I am only a user and not a profi
;-)
It could be a problem with the 'shielding' of the cable which goes from the
motherboard to the front panel. If this is not connected properly (or there
is no shield), some high speed USB devices may have problems.

Hope this helps, :)
--
Rob
Paul
2008-11-28 15:27:32 UTC
Permalink
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances?
If I connect the scanner to the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board.
Is there one possibility to test generally an USB-port for its
functionallity?
Thank you for comments, regards
Klaus Haber
You have one of these in the motherboard box.

Loading Image...

Disconnect the front panel USB wiring. Connect up the
2x5 USB cable of the 14-000012222 adapter. (You don't
need to connect the game port.)

Plug the scanner into the faceplate of the adapter.
Test the scanner. If it works with the Asus adapter,
but not with the computer wiring, then the computer
wiring is faulty.

HTH,
Paul
Rob
2008-11-28 17:38:00 UTC
Permalink
Post by Paul
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances? If I connect the scanner to
the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board. Is
there one possibility to test generally an USB-port for its
functionallity?
Thank you for comments, regards
Klaus Haber
You have one of these in the motherboard box.
http://estore.asus.com/images/14-000012222.JPG
Disconnect the front panel USB wiring. Connect up the
2x5 USB cable of the 14-000012222 adapter. (You don't
need to connect the game port.)
Plug the scanner into the faceplate of the adapter.
Test the scanner. If it works with the Asus adapter,
but not with the computer wiring, then the computer
wiring is faulty.
Thanks, Paul - I was struggling to explain, but a picture says a
thousand words!

Best Regards,
--
Rob
Klaus Haber
2008-11-28 20:03:22 UTC
Permalink
Hello Rob and Paul,
Post by Rob
Post by Paul
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
[...]
Post by Rob
Post by Paul
You have one of these in the motherboard box.
http://estore.asus.com/images/14-000012222.JPG
Disconnect the front panel USB wiring. Connect up the
2x5 USB cable of the 14-000012222 adapter. (You don't
need to connect the game port.)
Plug the scanner into the faceplate of the adapter.
Test the scanner. If it works with the Asus adapter,
but not with the computer wiring, then the computer
wiring is faulty.
Thanks, Paul - I was struggling to explain, but a picture says a
thousand words!
I took an overview about your links, they meet just the problem (so I hope)
I have. I will check all electrical connections and will follow your
recommendations. Unfortunally I got a visit at this time over the weekend.
So my proofings and results are available at the begin of the next week. I
will post them in this thread and hope, you will read them and we can
continue our discussion.
At this time the first thanks for your help.

Have a nice weekend,

regards

Klaus
--
Homepage: http://www.bingo-ev.de/~Klaus.Haber
"pH-Messung - einfach zu verstehen"
neu: "Eine Hundegeschichte"
http://www.bingo-ev.de/~Klaus.Haber/akita.html
daytripper
2008-11-28 22:21:29 UTC
Permalink
Post by Klaus Haber
Hello Rob and Paul,
Post by Rob
Post by Paul
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
[...]
Post by Rob
Post by Paul
You have one of these in the motherboard box.
http://estore.asus.com/images/14-000012222.JPG
Disconnect the front panel USB wiring. Connect up the
2x5 USB cable of the 14-000012222 adapter. (You don't
need to connect the game port.)
Plug the scanner into the faceplate of the adapter.
Test the scanner. If it works with the Asus adapter,
but not with the computer wiring, then the computer
wiring is faulty.
Thanks, Paul - I was struggling to explain, but a picture says a
thousand words!
I took an overview about your links, they meet just the problem (so I hope)
I have. I will check all electrical connections and will follow your
recommendations. Unfortunally I got a visit at this time over the weekend.
So my proofings and results are available at the begin of the next week. I
will post them in this thread and hope, you will read them and we can
continue our discussion.
At this time the first thanks for your help.
Have a nice weekend,
regards
Klaus
It's certainly worth a try and can't hurt, but given that everything else you
plug into the "malfunctioning" ports works fine, I suspect the scanner support
software...
GMAN
2008-11-29 08:03:56 UTC
Permalink
Post by Klaus Haber
Hello Rob and Paul,
Post by Rob
Post by Paul
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
[...]
Post by Rob
Post by Paul
You have one of these in the motherboard box.
http://estore.asus.com/images/14-000012222.JPG
Disconnect the front panel USB wiring. Connect up the
2x5 USB cable of the 14-000012222 adapter. (You don't
need to connect the game port.)
Plug the scanner into the faceplate of the adapter.
Test the scanner. If it works with the Asus adapter,
but not with the computer wiring, then the computer
wiring is faulty.
Thanks, Paul - I was struggling to explain, but a picture says a
thousand words!
I took an overview about your links, they meet just the problem (so I hope)
I have. I will check all electrical connections and will follow your
recommendations. Unfortunally I got a visit at this time over the weekend.
So my proofings and results are available at the begin of the next week. I
will post them in this thread and hope, you will read them and we can
continue our discussion.
At this time the first thanks for your help.
Have a nice weekend,
regards
Klaus
My wife got a visit too, he says he wont be leaving for another week or so!
Klaus Haber
2008-11-29 12:28:26 UTC
Permalink
Hello Paul,

I found some time to continue the discussion.
Post by Paul
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances?
If I connect the scanner to the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board.
Is there one possibility to test generally an USB-port for its
functionallity?
Thank you for comments, regards
Klaus Haber
You have one of these in the motherboard box.
http://estore.asus.com/images/14-000012222.JPG
Correct, I have this adapter (missing the game plug).
Post by Paul
Disconnect the front panel USB wiring. Connect up the
2x5 USB cable of the 14-000012222 adapter. (You don't
need to connect the game port.)
Plug the scanner into the faceplate of the adapter.
Test the scanner. If it works with the Asus adapter,
but not with the computer wiring, then the computer
wiring is faulty.
Maybe I didn't report exactly enough.

This adapter was installed due to the handbook of the motherboard since I
got the computer. I used this adapter all the time with success for all
commen hardware. Only the scanner was connected from the beginning to the
rear USB-port. The reason was the local arrangement of the scanner at the
table.

Some month ago I rearranged the local hardware and the scanner moved to a
place, from which it was easier to plug the USB-cable into the adapter at
the frontside than to the real. And since this rearrangement I got the
malfunction of the scanner. Therefor I don't believe, that the malfunction
is due to a failure in wiring or thomething else. If I connect the scanner
back to the realport, it is running well again. If I connect other
consumers (cameras, sticks, harddisks a.s.o.) to the same frontadapter,
they are also running well. That would demonstrate, that the wiring is ok.

An other point. As far as I know, there are two classes of USB-ports. I
don't mean the 1.x resp. 2.0 clas but the class of powersupply. One class
has a powercapacity of ~ 200 mA ( I don't know the exact value) and the
other class of ~ 500 mA (not the exact value). The first class is used by
hardware with low powerconsumption, the second one for high
powerconsumption. USB-hardware with high power will not run proper, if they
are connected to the lowpower USB-port. I took a look at ASUS Homepage, but
I did not found any information about the class of my ports at the
motherboard. My scanner has an own powersupply, so it should not be
necessary to use a lowpower-port.

At the other hand, the scanner will run at all 3 USB-ports at the laptop.

Grrrrrrrrrrrrrrrr, I don't understand this ;-)

@Rob

I studied your link exactly and I found nothing which did not meet my
wiring. From this point of view, every thing is wired right.

Can you (both) give some comments to the powersupply-classes of the
USB-ports in connection with the plugged consumers?

Regards

Klaus
--
Homepage: http://www.bingo-ev.de/~Klaus.Haber
"pH-Messung - einfach zu verstehen"
neu: "Eine Hundegeschichte"
http://www.bingo-ev.de/~Klaus.Haber/akita.html
Paul
2008-11-29 16:13:33 UTC
Permalink
Post by Klaus Haber
Hello Paul,
I found some time to continue the discussion.
Post by Paul
Post by Klaus Haber
Hello,
I use the ASUS-Board P5GD2 Deluxe. This board has totaly 8 USB 2.0-ports, 4
at the real panel direct connected and 4 ports at the front, connected by
cable to the board.
I found out, that 2 ports at the front will not work properly, if I connect
them to my Epson Scanner. If I do so, I get a failure message, that an
other scanner is already connected to the computer, which is not true. All
other 6 USB-ports are working well with the scanner. I changed the
USB-cable, no success. If I connect a camera, an USB-stick, an external
USB-harddisk to these both ports, they all work well, exception is the
scanner. I have no idea, what could be reason of this effect. Have the
different USB-ports also differnt valances?
If I connect the scanner to the different ports of my laptop, also no
problems. So I assume, that the failure should be at the ASUS-board.
Is there one possibility to test generally an USB-port for its
functionallity?
Thank you for comments, regards
Klaus Haber
You have one of these in the motherboard box.
http://estore.asus.com/images/14-000012222.JPG
Correct, I have this adapter (missing the game plug).
Post by Paul
Disconnect the front panel USB wiring. Connect up the
2x5 USB cable of the 14-000012222 adapter. (You don't
need to connect the game port.)
Plug the scanner into the faceplate of the adapter.
Test the scanner. If it works with the Asus adapter,
but not with the computer wiring, then the computer
wiring is faulty.
Maybe I didn't report exactly enough.
This adapter was installed due to the handbook of the motherboard since I
got the computer. I used this adapter all the time with success for all
commen hardware. Only the scanner was connected from the beginning to the
rear USB-port. The reason was the local arrangement of the scanner at the
table.
Some month ago I rearranged the local hardware and the scanner moved to a
place, from which it was easier to plug the USB-cable into the adapter at
the frontside than to the real. And since this rearrangement I got the
malfunction of the scanner. Therefor I don't believe, that the malfunction
is due to a failure in wiring or thomething else. If I connect the scanner
back to the realport, it is running well again. If I connect other
consumers (cameras, sticks, harddisks a.s.o.) to the same frontadapter,
they are also running well. That would demonstrate, that the wiring is ok.
An other point. As far as I know, there are two classes of USB-ports. I
don't mean the 1.x resp. 2.0 clas but the class of powersupply. One class
has a powercapacity of ~ 200 mA ( I don't know the exact value) and the
other class of ~ 500 mA (not the exact value). The first class is used by
hardware with low powerconsumption, the second one for high
powerconsumption. USB-hardware with high power will not run proper, if they
are connected to the lowpower USB-port. I took a look at ASUS Homepage, but
I did not found any information about the class of my ports at the
motherboard. My scanner has an own powersupply, so it should not be
necessary to use a lowpower-port.
At the other hand, the scanner will run at all 3 USB-ports at the laptop.
Grrrrrrrrrrrrrrrr, I don't understand this ;-)
@Rob
I studied your link exactly and I found nothing which did not meet my
wiring. From this point of view, every thing is wired right.
Can you (both) give some comments to the powersupply-classes of the
USB-ports in connection with the plugged consumers?
Regards
Klaus
As far as I know, the classes are 100mA and 500mA. All Asus motherboard
ports will be 500mA. There is a Polyfuse near each USB header, and it
is rated for more than 1 amp. The 1 amp is shared by the two USB ports.
So DC power should not be an issue. Each Asus port should meet the
high power spec.

The 100mA limit happens, when you use a bus powered hub connected to a
motherboard port. Like this.

500mA ----- 100mA
Motherboard_USB ------- bus_powered_hub ----- 100mA
----- 100mA
----- 100mA

The current limit still applies, even if the bus powered hub has only one
output port. An example of a one port hub, is a 5 meter USB active buffer cable.

500mA
Motherboard_USB ------- 5_meter_buffer_cable (one port hub) ----- 100mA

Bus_powered means all power is derived from the original 500mA
limit.

If the scanner works with the adapter I described (this one) -

http://estore.asus.com/images/14-000012222.JPG

but not with the computer case wiring, then the computer
case wiring is not working correctly. As a front panel
substitute, you can use a 5 1/4" drive bay USB panel
as a substitute. For cabling, what you want is a minimum
of loose wire. If the loose wires here were part of the
USB cable, the electrical performance might not be
very good. USB2 is a 400Mbit/sec signal, and the signal
should be maintained in a transmission line environment.
Single loose wires, with no ground reference, don't have
a precisely defined impedance, and signal reflections
result.

Loading Image...

To give an example of the problem, I have an Antec case
here, where the front USB port only runs at USB 1.1 speeds.
This is a known problem with the cable and PCB assembly that
Antec shipped with a number of their older computer
cases. Antec has improved the design, with their latest
stuff. I haven't heard of problems with the more recent
cases.

Paul
Klaus Haber
2008-11-30 13:54:33 UTC
Permalink
Hello Paul,
Post by Paul
Post by Klaus Haber
Hello Paul,
I found some time to continue the discussion.
[...]
Post by Paul
As far as I know, the classes are 100mA and 500mA. All Asus motherboard
ports will be 500mA. There is a Polyfuse near each USB header, and it
is rated for more than 1 amp. The 1 amp is shared by the two USB ports.
So DC power should not be an issue. Each Asus port should meet the
high power spec.
ok.
Post by Paul
The 100mA limit happens, when you use a bus powered hub connected to a
motherboard port. Like this.
500mA ----- 100mA
Motherboard_USB ------- bus_powered_hub ----- 100mA
----- 100mA
----- 100mA
The current limit still applies, even if the bus powered hub has only one
output port. An example of a one port hub, is a 5 meter USB active buffer cable.
500mA
Motherboard_USB ------- 5_meter_buffer_cable (one port hub) ----- 100mA
Bus_powered means all power is derived from the original 500mA
limit.
If the scanner works with the adapter I described (this one) -
http://estore.asus.com/images/14-000012222.JPG
but not with the computer case wiring, then the computer
case wiring is not working correctly. As a front panel
substitute, you can use a 5 1/4" drive bay USB panel
as a substitute. For cabling, what you want is a minimum
of loose wire. If the loose wires here were part of the
USB cable, the electrical performance might not be
very good. USB2 is a 400Mbit/sec signal, and the signal
should be maintained in a transmission line environment.
Single loose wires, with no ground reference, don't have
a precisely defined impedance, and signal reflections
result.
In my eyes it is very clear now, where to find the failure. I have in total
2 panels which each 2 USB-ports: One frontpanel with 2 ports and one
realpanel with 2 ports. Both motherboard headers are connected by cable to
these 2 panels. The frontpanel ist the malfunction equipment, the realpanel
ist working well. And now I changed the cables so, that the frontpanel was
fit into the header of the realpanel and the realpanel was fit into the
header of the frontpanel.
Result: The frontpanel USB ist working well now and the realpanel USB has
malfunction. That means, that the cables of the 2 panels are ok, but one
USB-header at the motherbord is not working well - let's say not working
well for the scanner. Because I see no change to "repair" the motherboard,
I leave this configuration. It ist now locally easier to fit the scanner
cable into the front USB port. For the other equipment, which is always
fixed connected by USB cables, the real ports are good, because they don't
indicate any failure.

Very interesting for me!

Thanks again for your help,

regards

Klaus
--
Homepage: http://www.bingo-ev.de/~Klaus.Haber
"pH-Messung - einfach zu verstehen"
neu: "Eine Hundegeschichte"
http://www.bingo-ev.de/~Klaus.Haber/akita.html
Paul
2008-11-30 22:20:48 UTC
Permalink
Post by Klaus Haber
In my eyes it is very clear now, where to find the failure. I have in total
2 panels which each 2 USB-ports: One frontpanel with 2 ports and one
realpanel with 2 ports. Both motherboard headers are connected by cable to
these 2 panels. The frontpanel ist the malfunction equipment, the realpanel
ist working well. And now I changed the cables so, that the frontpanel was
fit into the header of the realpanel and the realpanel was fit into the
header of the frontpanel.
Result: The frontpanel USB ist working well now and the realpanel USB has
malfunction. That means, that the cables of the 2 panels are ok, but one
USB-header at the motherbord is not working well - let's say not working
well for the scanner. Because I see no change to "repair" the motherboard,
I leave this configuration. It ist now locally easier to fit the scanner
cable into the front USB port. For the other equipment, which is always
fixed connected by USB cables, the real ports are good, because they don't
indicate any failure.
Very interesting for me!
Thanks again for your help,
regards
Klaus
That is why they give you so many USB ports. In case
some of them break :-)

Paul

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