A8N SLI Deluxe - no audio output anymore on any connector.

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

I tried plugging in an old set of speakers with a dodgy AC adaptor,
and now the PC won't output any audio... when I try to get it to sense
the connectors, it says failed for all of them. What could be the
problem here?? Thanks for any help :(
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More about deluxe audio output anymore connector
  1. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    In article <44ltb1d5fplr5e3vv2dq0c0b7l9ba8fq5o@4ax.com>, N-Bomb
    <nick89gx.at@at.rogers.com> wrote:

    > I tried plugging in an old set of speakers with a dodgy AC adaptor,
    > and now the PC won't output any audio... when I try to get it to sense
    > the connectors, it says failed for all of them. What could be the
    > problem here?? Thanks for any help :(

    What exactly is a "dodgy AC adapter" ? Are you getting a shock from
    the product, implying AC is leaking through to the input side ?

    Ideally, amplified computer speakers should have isolated power. Something
    like a two prong plug, as that implies the computer will be establishing
    the ground level.

    All the AC'97 sound reference designs I've looked at, use AC coupling
    of the inputs and outputs. The "strong drive" ports, like anything intended
    for driving headphones, might use 100 microfarad (uf) capacitors for that
    coupling, while input channels or weak (600 ohm) outputs use 1 microfarad
    caps (likely ceramic). If a high DC voltage is applied to a large capacitor
    like that, it could be the inrush current could fry the AC'97 chip. If a
    high AC voltage is applied, you could exceed the breakdown voltage of the
    chip pins.

    It could be, that somehow your speaker setup has driven current backwards
    into the jacks on the motherboard. If there was DC voltage greater than
    the breakdown voltage on the caps for example.

    Looking at the ALC850 datasheet, it is unclear how their jack sense
    works. The registers in the chip consist of:

    MX66 Sense Function (can be set to sense tip or ring contact of 6 stereo jacks)
    0h: FRONT-OUT (pin-35/36)
    1h: SURR-OUT (pin-39/41)
    2h: CEN/LFE-Out (pin-43/44).
    5h: MIC1 In (pin-21)
    6h: MIC2 In (pin-22)
    7h: LINE In (pin-23/24)

    MX68 Sense Function Information (indicates sense cycle worked or not)
    Information Valid bit, IV
    0:After a sense cycle is completed indicates that no information is
    provided on the sensing method
    1:After a sense cycle is completed indicates that information is
    provided on the sensing method

    MX6A Sense Detail (sense cycle identifies device plugged into jack)
    S[4:0]
    For output jacks:
    02h: Not specified or unknown
    05h: Powered speaker
    06h: Earphone or passive speaker
    For input jacks:
    12h: Not specified or unknown
    13h: Mono Microphone
    15h: Stereo Line-In

    so it sounds like the chip is no longer returning "information valid".

    Either return the motherboard under warranty, and get it fixed, or
    simply plug in a separate sound card and use that. I doubt the problem
    is software related, but if you want, using Add/Remove, uninstall the
    software, then reinstall the software package. If it still isn't
    working, it is likely some fried hardware.

    To know more, you would need to see what voltage shows up on the 1/8"
    stereo plugs on your "dodgy" speakers, with respect to the ground level
    of your computer case. Using a voltmeter, measure from computer chassis
    to the tip and ring contacts of the speakers. Try the voltmeter on the
    high AC range, and then switch to high DC range, and measure again. (You
    want to use a high range, so the voltmeter isn't damaged.) You might
    get some idea of what is leaking out of the speakers plugs, waiting to kill
    whatever it is plugged into.

    Paul
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