Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
Is your P5AD2 the "E" version? Latest BIOS 1003 for the "E" claims to have
changed the way the jacks work.
However I have had trouble getting 1003 to work on my P5AD2-E. Make sure you
have 1002 available to put back on the board if you have problems.
Barry
"Paul" <nospam@needed.com> wrote in message
news:nospam-3101050450220001@192.168.1.177...
> In article <1107160562.281265.251420@f14g2000cwb.googlegroups.com>,
> "andyw" <andyww14@hotmail.com> wrote:
>
> > Hello,
> >
> > My PC has started to develop an incredibly annoying problem.
> >
> > After a random time of using the PC the CMI "Smart Jack" utility will
> > keep opening to report that a speaker wire had been removed.
> >
> > This impacts what ever I'm doing, I could be playing a game and it will
> > come out of the came back to the desktop, watching a film and the same
> > things happen.
> >
> > Of course no wire are being removed and they are securely fastened.
> > I've connected them up to a 7.1 system.
> >
> > A reboot will cure the problem as the more you reset or close the Smart
> > Jack window the more frequently it reopens.
> >
> > Any idea what has occurred to make this happen? And how I could fix it.
> > Reinstallations of the drivers do not help.
> >
> > Thanks,
> >
> > Andy.
>
> If you look at page 31, it shows how the jack sense works.
>
http://cmedia.com.tw/doc/C-Media%20CMI9880%20Datasheet%20rev%200.99C.pdf
>
> There are two sense pins - SenseA and SenseB. Each sense pin can
> handle four switches. By using binary weighted resistors, the
> sixteen possible combinations of switch closures on the four
> switches, cause a varying voltage to be made available on
> a sense pin. (There is likely a Vref and a fixed resistor value
> inside the CMI9880, to complete the circuit. There is a voltage
> divider action between the resistor network outside the chip,
> and whatever fixes the current flowing out of the pin on the
> chip.)
>
> Inside the CMI9880, there is an analog to digital converter, that
> converts the sixteen possible voltage values, back into a four
> bit code from 0000 to 1111.
>
> This is a clever way of transmitting four bits of information over
> a single wire, and is used to reduce the number of pins needed on
> the IC package for the jack sense function.
>
> Now, why did I explain all of this ? Just to suggest there is a
> lot going on there, and thus a lot of ways a failure can occur.
> Some ways it can screw up:
>
> 1) Internal reference inside CMI9880 is varying. But you would
> likely notice something funny going on with the output sound,
> if that was happening.
> 2) A switch contact inside one of the jacks is not making good
> contact. This would cause the value coming from the ADC inside
> the CMI9880 to "dither". It would see 1101, then 1100, then
> 1101 or the like. Each of those transitions would cause the
> CMI smart jack panel to appear on the screen.
>
> The Azalia jacks have three pins for the 1/8" stereo plug,
> and also have a contact pair that connects to the resistor
> network. All it would take, is an undersized 1/8" stereo plug,
> or a bad contact on the contact pair, to cause that to
> happen.
> 3) One of the resistors in the resistor network is out of tolerance.
> I have seen surface mount resistors crack - the body is made
> of glass, and the wrong temperature profile or pad shape can
> cause a lot of stress on them.
>
> Another possibility, is you've connected something to the
> AAFP audio header. There are pins in your user manual,
> labelled "sense1_return", "sense2_return", and "sense_send".
> These three pins could be connected to two resistors of
> the four resistor network above. If you aren't using an Azalia
> audio cable on this header, then nothing should be connected
> to those pins. Any connection that screws up the resistor
> network, could result in the ADC in the 9880 mis-sensing the
> voltage on SenseA or SenseB.
>
> If none of the above is suggesting any fault you can check
> for (including a short from an extra standoff, to something on
> the bottom of the motherboard), you may need to RMA the board
> to get it fixed.
>
> Could this be a driver problem ? I haven't a clue. I mean,
> it could be something as simple as two instances of some driver
> running or something. It is pretty hard though, to suggest what
> to look for.
>
> The V5.12.01.0008.51.61 driver, dated Jan12/2005, is the latest
> driver, and is available on the Asus download page. It is a
> huge download, and most of the download is for a multi language
> Microsoft UAA driver. (I pity the dial-up modem users out
> there...) If you want to try this one, uninstall the old stuff
> first.
>
> ftp://ftp.asus.com.tw/pub/ASUS/misc/audio/c-media/cmi9880/
>
> Page 172 of Rev 1.0 of the Intel HDaudio spec also has some
> info on how the jack sense is supposed to work. The Intel
> spec says the CMI9880 should be waiting 0.25 seconds, before
> declaring a jack has changed states, so whatever is wrong,
> it is lasting for at least 0.25 seconds.
>
>
ftp://download.intel.com/standards/hdaudio/pdf/HDAudio_03.pdf
>
> HTH,
> Paul
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