P4S533 USB header pin assignments

  • Thread starter Thread starter Krick
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Krick

condraj said:
I've been trying unsuccessfully to connect two front-panel USB ports to the
extra USB header on my P4S533. I have the two extra rear ports (that came
with the motherboard) connected to header USB2 and they work fine. However,
connecting the unused header, USB3, to the front ports doesn't work. I've
tried switching the USB2 and USB3 connections, and either header will work
with the original (rear) port card, and neither will work with the front
port. I have the front connector wired according to the pin assignments in
the P4S533 manual:

Red: USB power
White: USB -
Green: USB +
Black: GND
Gray: OC1#

In reading a thread on another newsgroup, I found a person with a similar
problem who solved it by reversing the white (-) and green (+) wires on his
front port connectors. If that really works, then I'd have to conclude that
the pin assignments listed in the motherboard manual must be incorrect.

Before I try reversing the + and - connectors on my USB port (and perhaps
fry something in the process), I wanted to see if any of you has any insight
into the problem.

Has anybody succeeded in connecting USB2 or USB3 to an additional port? If
so, what pin assignments did you use? Thanks much.
Jon
Click to expand...

I successfully connected an Antec EasyUSB 2.0 unit to one of the
motherboard headers on my ASUS P4S533.

The default wiring that came with the unit didn't work at all. In
fact, hooking it up disabled all my USB ports.


The antec unit's cable had the following pinout:

red: 6 1 :empty
white: 7 2 :yellow
green: 8 3 :grey
black: 9 4 :black
key:10 5 :blue

Looking at the small circuit board where the USB ports are attached,
pins #6 and #1 are connected (USB POWER) and pins #9, #4, and #5 are
connected (GND)

Aparently, on the P4S533, pin 5 is something special called OC1# that
doesn't like being connected to ground.

So after looking at the USB pinout from my P4S533 manual, I decided to
modify the USB cable by moving the blue wire from pin #5 to pin #1. I
could have also just removed it completely but then I would have had
to cut the wire or insulated it with tape or something. Moving it was
just easier and it gives me a dual USB power wire.

new pinout:

red: 6 1 :blue
white: 7 2 :yellow
green: 8 3 :grey
black: 9 4 :black
key:10 5 :empty


Now it works like a charm.

....
Krick
 
I successfully connected an Antec EasyUSB 2.0 unit to one of the
motherboard headers on my ASUS P4S533.

The default wiring that came with the unit didn't work at all. In
fact, hooking it up disabled all my USB ports.


The antec unit's cable had the following pinout:

red: 6 1 :empty
white: 7 2 :yellow
green: 8 3 :grey
black: 9 4 :black
key:10 5 :blue

Looking at the small circuit board where the USB ports are attached,
pins #6 and #1 are connected (USB POWER) and pins #9, #4, and #5 are
connected (GND)

Aparently, on the P4S533, pin 5 is something special called OC1# that
doesn't like being connected to ground.

So after looking at the USB pinout from my P4S533 manual, I decided to
modify the USB cable by moving the blue wire from pin #5 to pin #1. I
could have also just removed it completely but then I would have had
to cut the wire or insulated it with tape or something. Moving it was
just easier and it gives me a dual USB power wire.

new pinout:

red: 6 1 :blue
white: 7 2 :yellow
green: 8 3 :grey
black: 9 4 :black
key:10 5 :empty


Now it works like a charm.

...
Krick
Click to expand...

With regard to the original comment "motherboard manual must be incorrect",
so far the stuff I've been reading identifies the case manufacturer
as the negligent party, not the motherboard. Where the motherboard part
can be misleading, is the cases where it appears there a components on
the supplied adapter plate, that would be missing if using the case wiring
instead. For any computer case you buy, I recommend using an ohmmeter to
verify that the names printed on the case wires correspond to the
proper pins on the case connector - failure to do this could result
in a burned peripheral device.

As for the OC1# pin, I tried looking in the USB 2.0 standard, and
don't see it mentioned. A guess is it stands for "over current one,
active low". How this would work is, if the OC1# signal is grounded,
the motherboard shuts off power to the USB connectors. Most Asus
motherboards use Polyfuse automatically recovering fuses for this
function, where protection is needed. I guess this was an attempt to
get the adapter board to send a signal when an overcurrent situation
was detected. Leaving this signal alone (i.e. open circuit) is a
good idea.

HTH,
Paul
 
There was a chinese manufacturer that made a whole batch of USB
connectors incorrectly wired. About 1 million connectors, and most of
them went to Taiwan case maunfacturers.

Be extremely careful when wiring front panel USB connectors to a
motherboard. If you get it wrong (regarless of whose mistake it was),
you can fry both the USB device and the motherboard USB port the first
time that you TRY to use it (depends, of course, on just HOW you "got it
wrong").
 
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