Flash drive not recognized when plugged into front USB port

R

Ray K

I have three flash drives that my newly built computer recognizes when
plugged into the USB ports on the back panel of my Asus M3A76-CM mob.
Windows Explorer correctly shows them as the L: drive and the Safely
Remove Icon appears in the system tray.

But when I plug them into the front, they don't work. The system tray,
Safely Remove Icon appears, along with the right drive letter L:, but
Windows Explorer doesn't show the device. If I try using the Safely
Remove Icon to stop the drive, I can't do it. I end up rebooting the
computer.

Each front USB port is connected to the mobo by four wires: Red, Vcc,
White, D-, Green, D+, and Black ground, in that order. I tried swapping
the green and white leads, but then the computer shows a New Hardware
Found message, but couldn't recognize it with these leads theoretically
wrong.

If I again plug the devices into the back USB port, they still work
okay, so I haven't damaged them due to improper wiring to the front ports.

Thanks for your suggestions.

Ray
 
R

Ray K

Andy said:
The front panel USB cable is substandard.

I've reused the case, so both front connectors and their cables are the
same ones that had been working right along, as USB2.0. The cables are
round, slightly thinner than a standard #2 round pencil. The mobo manual
warns not to use a 1394 cable to the USB connectors; doing so will
damage the motherboard. I don't know what a 1394 cable is, but since I
haven't damaged the mobo, I'm assuming that the cables to the front
panel are not 1394s.
 
G

GlowingBlueMist

Jan said:
I've had similar issues with front USB connectors. I have an Antec
case with two front USB ports. They will read USB flashdrives but
when I plug a 2.5" form factor external drive into either one of the
ports they will not work. I would get a clicking sound from the drive
as if it were indicating it was on its death bed. Plugging the drive
into a rear USB connector would get the drive running fine. When this
happened for the first time I emailed Antec, as the case was under
warranty (I believe for 3 years). They sent me a replacement front
port USB connector assembly, which included the wiring harness. Same
problem hooking it up. So the issue is still unresolved. It could
very well be that the headers on the new Gigabyte mb I have are OK
for flash drives, but allow insufficient current to allow the
external drive to run with my system. My guess in your case, since
the front ports were working OK for the previous install is that the
mb front USB headers have the same issue as mine, but even worse to
not allow reading of a lowly flash drive current requirement. Maybe
it's worth getting in touch with Asus since they may already be aware
of the issue and may have a fix for it, or may have a correction to
the point of wanting to replace your mb. By the way, the '1394' refers to
a firewire cable.

Here is a link showing two common methods of attaching the pins to the
headers as not all motherboards use the same header wiring. Compare the
instructions to your motherboard pin outs and see if it helps get things
working for you. The wire color code info may come in handy if the
motherboard pins don't match what the plug was initially wired for.

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

The connectors on many of the front panel USB port extenders are cheaply
made. After a couple of plug and unplug cycles the individual connectors
within the plugs tend to loosen up and may not make a good connection on the
motherboard header pins.

If you are able to remove the individual plugs from the plastic you may be
able to tighten them up a little and make a better connection. If nothing
else was wrong and you get them working this way you can then put them back
into the plastic plug holder. Just be sure to do the "pull" (for tightness)
testing on the individual plugs with the motherboard power off. The same
for when you plug them all onto the header(s) when ready for a full power
test. They can short out very easily with the plastic plug cover removed.
 
R

Ray K

GlowingBlueMist said:
Here is a link showing two common methods of attaching the pins to the
headers as not all motherboards use the same header wiring. Compare the
instructions to your motherboard pin outs and see if it helps get things
working for you. The wire color code info may come in handy if the
motherboard pins don't match what the plug was initially wired for.

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

My mobo has the Intel header arrangement. Each of the two cables from
the front panel has four separated pins at the mobo end, without a
separate ground/shield wire.

I've submitted the question to Asus forums.

The connectors on many of the front panel USB port extenders are cheaply
made. After a couple of plug and unplug cycles the individual connectors
within the plugs tend to loosen up and may not make a good connection on the
motherboard header pins.

I don't think this applies in my case.
If you are able to remove the individual plugs from the plastic you may be
able to tighten them up a little and make a better connection.

Can't do this. The front connectors are in a sealed plastic housing.
 
R

Ray K

From more googling around, I found the solution. In Device Manager,
under View, click on Show Hidden Devices. Expand Universal Serial Bus
Controllers. If any of the entries are shown in gray, right click on
each and Uninstall it. That's it. I didn't have to reboot for the front
ports to start working.

I also had a category called Other, with three subentries. I also
uninstalled them.

Problem is, next time I rebooted, there were no more grayed USB entries
and the Other category stayed uninstalled but the original problem of
flash drives not being recognized returned.

Out of curiosity, I plugged a USB external floppy drive into the front
panel and XP immediately recognized it and assigned a: as the drive
letter; I also transferred files to it okay. Then when I tried a flash
drive, XP continued to recognize it, even after rebooting and even if I
plug two in at once.

I never thought to try transferring my USB printer from the rear port to
the front.

I guess the real key was getting rid of the hidden USB devices and
trying a non-flash device in the front.

Other advice, which I did not have to do, includes uninstalling the USB
host controllers, rebooting, and letting Windows reinstall them. This
will temporarily disable your USB/wireless mouse.

Ray
 

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