Crash said:
The USB connectors on the fronts of a few of my computers don't work.
I'll get the message that the device isn't recognized, etc.
I can connect a usb jack that would go in an expansion slot, but usually
these cables are just long enough to reach from the back of the case to the
Mobo.
I would think the jacks would be backward compatible, but I guess they are
not.
Any suggestions?
There were some Antec computer cases, where the wiring assembly in the
front is really only good enough for USB 1.1 . Antec was offering to
replace the assembly in the front, with one designed to do USB 2.0.
A fair number of computer case models were affected - there used to
be an Antec web page with a list of the cases, but it was soon removed.
You can get devices like this, that sit in a drive bay. A really well
designed one, might leave room for the disk drive as well.
Koutech KW-F7771-B FireWire 1394a + USB 2.0 Combo Internal Front Bay
http://www.newegg.com/Product/Product.aspx?Item=N82E16815104225
SILVERSTONE SST-FP32-S Aluminum USB/1394/Audio Panel ( Silver )
http://www.newegg.com/Product/Product.aspx?Item=N82E16813999355
The ideal USB adapter design should have a short section of loose wires
down near the motherboard header end. The cable is supposed to have a
controlled characteristic, and the longer the loose wire is, the less
controlled the result is.
http://estore.asus.com/images/14-000012222.JPG
USB adapter boards can have a few analog components on them for filtering.
There may be small resistors, capacitors, and inductors. In addition,
there could be a larger electrolytic, and the job of that capacitor,
is to filter the power, just as it goes to the USB device being plugged in.
While these docs aren't very exciting reading, they do cover a few
issues for computer design and USB on the faceplate. In fact, these
docs don't spell out all the mistakes they can make, when providing
USB front access.
http://www.intel.com/technology/usb/download/usb2dg_r1_0.pdf
http://www.usb.org/developers/whitepapers/power_delivery_motherboards.pdf
This one covers FPIO connections for audio, Firewire, USB and so on.
http://www.formfactors.org/developer/specs/fpio_design_guideline.pdf
There are a few variations as to how the 2x5 header on the motherboard
is wired. Sometimes, an adapter and a motherboard, don't exactly agree,
and then some wires have to be moved around.
http://www.frontx.com/cpx101_2.html
This shows how to move the wires around, on the adapter cable end.
There are delicate plastic tabs you lift with a hobby knife, to allow
the wire and pin to be backed out. The pin then snaps into place, when
you reinsert it.
http://www.frontx.com/head_con.html
HTH,
Paul
