No microphone input with P4P800S

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I just built a new system using a P4P800S, running Windows XP. The sound
header is attached to the jacks on the front panel of my (Antec Sonata)
enclosure. The output is fine. The input appears to be dead.

The control panel says the sound input is enabled, with volume set to
mid-range. Windows Sound Recorder registers nothing.

I've tried two different headsets with the same results, so the problem is
not there.

The possibilities I see are: a configuration problem; a failure on the
motherboard that affects input only; a problem in the front panel or the
cable that connects it to the motherboard. No ideas on how to test for or
identify any of those.

Any suggestions?
 
news.west.earthlink.net said:
I just built a new system using a P4P800S, running Windows XP. The sound
header is attached to the jacks on the front panel of my (Antec Sonata)
enclosure. The output is fine. The input appears to be dead.

The control panel says the sound input is enabled, with volume set to
mid-range. Windows Sound Recorder registers nothing.

I've tried two different headsets with the same results, so the problem is
not there.

The possibilities I see are: a configuration problem; a failure on the
motherboard that affects input only; a problem in the front panel or the
cable that connects it to the motherboard. No ideas on how to test for or
identify any of those.

Any suggestions?
Click to expand...

1) Remove microphone cabling from FP_AUDIO header.
2) Touch your finger to the MIC2 pin on the header.
You should get some "hum" coupled into the recorder.
That is one way to get a signal to test with.

The second option is to leave the cabling as is, then get a
portable audio device, like a Walkman or MP3 player etc, and
plug it into the microphone port. What this does, is at
least guarantee that you have a signal source that works.
It could be that the microphone is putting out too low level
a signal, and the higher voltage you get from a Walkman will
at least allow you to test the wiring and hardware.

A mistake on some cases, is the MIC2 and MIC_BIAS wires are
mislabelled and switched with one another. There was an Antec
web page with this info on it, but the butt heads changed the
link, so if you want to verify my info, you have some searching
to do. (Antec is famous for messing up case wiring. So far
none of their mistakes have killed any hardware.)

In any case, reversing MIC2 and MIC_BIAS wires won't hurt
anything, because MIC_BIAS has a current limiting resistor
on the motherboard. Give it a try.

HTH,
Paul
 
A mistake on some cases, is the MIC2 and MIC_BIAS wires are
mislabelled and switched with one another. There was an Antec
web page with this info on it, but the butt heads changed the
link, so if you want to verify my info, you have some searching
to do...
Click to expand...

Ah, that was it! I had to dive under the desk to deal with an unrelated
problem, and I discovered (duh) that the motherboard has its own set of
sound connectors on the back panel. They work fine.

I will contact Antec and see what they have to say. Meanwhile, I will post
my remaining P4P800S questions in a new thread titled "P4P800S, three little
problems," and see if my luck holds.
 
Further adventures...

I found a FAQ on the Antec web site which puts a different spin on the
problem. They say that different motherboard manufacturers use different
pin-outs for the Intel front panel audio, so some of their cases provide
seven individual pin connectors rather than a single header.

I got a single header on mine, so that doesn't do me any good. Before I
contact Antec I want to understand the situation completely, and that is
proving difficult. Their party line implies that there IS no standard
pin-out, so it would be pointless to take them to task for not conforming to
it.

I have found several "answer man" web sites which refer to
www.frontx.com/cpx110.html for the standard pin-out. The multiple references
make it credible to me, but it would have no authority in a debate with
Antec. It's just some information fromanother vendor with a front-panel
product, and if Antec says it's wrong, I have nothing to reply with.

Intel's web site search function is so brain-damaged that I can't find any
useful information with it. I can't even find out which of their own
motherboards has this header, so that I can look up the technical
specifications and cite them as a de facto standard.

Paul, do know any sources that will be useful for me?
 
Jonathan Sachs said:
Further adventures...

I found a FAQ on the Antec web site which puts a different spin on the
problem. They say that different motherboard manufacturers use different
pin-outs for the Intel front panel audio, so some of their cases provide
seven individual pin connectors rather than a single header.

I got a single header on mine, so that doesn't do me any good. Before I
contact Antec I want to understand the situation completely, and that is
proving difficult. Their party line implies that there IS no standard
pin-out, so it would be pointless to take them to task for not conforming to
it.

I have found several "answer man" web sites which refer to
www.frontx.com/cpx110.html for the standard pin-out. The multiple references
make it credible to me, but it would have no authority in a debate with
Antec. It's just some information fromanother vendor with a front-panel
product, and if Antec says it's wrong, I have nothing to reply with.

Intel's web site search function is so brain-damaged that I can't find any
useful information with it. I can't even find out which of their own
motherboards has this header, so that I can look up the technical
specifications and cite them as a de facto standard.

Paul, do know any sources that will be useful for me?
Click to expand...

There is a standard. Pg.20 gives the pinout. Same pinout as
Asus motherboard headers (at least the modern motherboards).

http://www.formfactors.org/developer/specs/fpio_design_guideline.pdf

If the cabling in the Antec case consists of a 2x5 plastic
shroud, with the wires and pins housed inside it, look for a
plastic release tab for each pin on the side of the shroud. It
holds the pin in place, and the pin can be dislodged by prying
on the tab with a hobby knife (xacto knife). The figure at the
bottom of this page demonstrates how to do it.

http://frontx.com/head_con.html

I hope the wires are color coded and you have some info from Antec
as to which color corresponds to which function, because you'll
need that to move the pins from their current position to a new
position.

All I can tell you, is there was an Antec FAQ which was basically
switching the function of the MIC2 and MIC_BIAS pins. Since in that
case the wires were separate, and each one had text printed on the
plastic at the end of the wire, the implication was that they
mislabelled the two pins.

In the end, this is where you want the signals from the motherboard
to go. MIC2 from the motherboard header should end up contacting
the Tip contact. MIC_BIAS (a.k.a MICPWR) goes to the Ring contact.
The Sleeve contact goes to ground (GND).

"MIC Input Characteristics"
http://www.a-tech.net/SoundCards/CT4811.htm

/ \
MIC2 ------| |
\ /
+===+
MICPWR -----| | 3.5mm plug
|===| to soundcard
| |
GND -------| |
| |
+=======+
| |

If you buy a 3.5mm (1/8") plug from Radio Shack, you can
plug that into the case and gain access to the contacts.
You can then use an ohmmeter, to verify the names of the
above wires.

I own a couple of Antec cases, and strongly recommend checking
the pinout of the connectors with an ohmmeter. On one case,
the Firewire data connections are reversed. The Firewire and
USB connectors have their grounds wired together inside
the case. Antec just isn't that swift when it comes to wiring.
(I do like their cases and power supplies, despite this.)

HTH,
Paul
 
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