Jethro said:
hi guys, as above ... what is the magic code to indicate a mobo has
the pins to plug a front panel into ?
thanks
http://www.giga-byte.com.tw/Products/Motherboard/Products_Spec.aspx?ProductID=1349
Generally, you have to look in the manual, to see if there is an FP_AUDIO
header. Web sites will usually tell you, that there is an AC'97 or HDaudio
CODEC, but they don't usually tell you about the FP_AUDIO header in the
advertising. Modern boards adhere, more or less, to the Intel 2x5 standard,
with the two jumper plugs for continuity in the case of AC'97. HDaudio,
on the other hand, doesn't need the jumpers, as separate signal sources
are available for everything.
Now, I downloaded the manual, and the 8idx_e pinout is non-standard.
The connector is called F_Audio. The thing that concerns me, is there
is a +12V pin next to low level pins, like a microphone pin. If the board
was for my own personal use, I'd probably take my fine cutters, and cut
that +12V pin off flush with the board (to reduce the risk of shorting,
or of accidentally connecting audio wires to it. It is probably meant
to power a headphone amplifier of some sort.
The pins of some interest would be the lower seven shown in the picture
in the manual.
MIC X X GND
Front_Audio_R X X Rear_Audio_R (a.k.a RET_R)
Front_Audio_L X X Rear_Audio_L (a.k.a RET_L)
GND X
The microphone jack is going to be missing a critical connection.
Microphone Tip, Ring, and Sleeve are normally MIC, MIC_BIAS, and GND.
There is no MIC_BIAS or MIC_PWR on the above header, so if you plug
in an electret microphone, it isn't going to work. A piezoelectric
microphone may be OK, and a dynamic one would probably be too weak to
be heard (even with 20dB boost button engaged). So, you can connect
MIC and GND to the microphone jack, but the second contact on the
jack will be floating and not connected.
For headphones, Tip, Ring, and Sleeve would be Left, Right, and GND.
Front_Audio_L, Front_Audio_R, and GND would do for that. The jack
may include two "return" signals, RET_L and RET_R and they'd go on
the two pins on the right.
Some case wiring is missing the RET_L and RET_R, in which case the
rear Line_out (green) jack will no longer function when the two
jumpers are removed. Cases that have the return wires RET_L and
RET_R allow the signal to be brought back to the motherboard, and
RET_R and RET_L go direct to the tip and ring contacts of the
rear green connector. So if your rear sound no longer works the way
you expected, chances are something isn't right with the returned
signals RET_R and RET_L. In some cases, I have to recommend to people,
that they scrap the idea of using the front wiring, if the wiring
is so non-standard as to flub the return thing.
When not using front panel audio wiring, put the two jumpers back.
The jumpers would go like this, as shown in the manual.
MIC X X GND
Front_Audio_R X<--->X Rear_Audio_R (a.k.a RET_R)
Front_Audio_L X<--->X Rear_Audio_L (a.k.a RET_L)
GND X
In this picture, you can still see the two white jumpers in place
on the above set of pins. The F_Audio header stretches from left
to right, with the Front_Audio_R and friends, on the right hand
end of the pin header. The diagrams above are drawn, to make it
easier to type in signal names, and needs to be rotated to fit
the actual picture.
http://www.baber.com/baber/gifs/411gifs/8idx.jpg
HTH,
Paul
