Manually figuring out the pinout..

Discussion in 'General Electronics Chat' started by brontozaur, Dec 20, 2015.

  1. brontozaur

    Thread Starter New Member

    Dec 20, 2015
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    Hi there,

    I have an ATI PCI-E graphics card that I need to use for VHS video capture.
    The problem is that this card has a non-standard 32pin input/output breakout
    socket, and I don't have the original breakout cable. Original cable
    is rare to find and unreasonably expensive, and there is no pinout posted on the web.
    Of those 32 pins, there is vga out, s-video in/out, maybe also audio in/out.
    I just need to figure out which 4 pins out of those 32 is S-VIDEO-IN
    (luma, chroma and two grounds; all the pins pierce through the PCB and fully
    visible on the backside). I could then remove that [mildly offensive word removed] socket with a heat gun and install a nice s-video-in socket.
    How do I do that with a multimeter without frying the card? How would you go about this?
    Any help would be much appreciated..
     
    Last edited by a moderator: Dec 22, 2015
  2. sailorjoe

    Member

    Jun 4, 2013
    361
    63
    Hmmm, interesting problem. Do you have a part number for the board? I looked at pictures of several ATI's and didn't see one with a 32 pin connector. What chips are on the board? If it was me, I would first look on line for a schematic of the board, then try to find pinouts of the chips on the board. If I couldn't get either one, I'd try to recreate a portion of the circuit by following the traces. It's a place to start, but honestly it's tedious detailed work.
     
  3. brontozaur

    Thread Starter New Member

    Dec 20, 2015
    11
    0
    It is 109-A46404-00 (All in Wonder x600 pro). The analog video chip is ATI rage theater 200 (213T20ZQA12).
    It is obviously a multilayered PCB, i can't see any traces on the surface running from that socket.
    Anyways I was thinking - 1) find all the grounds - these are probably all connected so resistance between them all should be very low? 2) find all the OUTPUTS - use external ground and measure voltage pin by pin while playing a video. Now that all outputs and grounds have been figured out, I can just try all the different input combinations until I see the image from the VCR on the computer screen. The voltage of both luma and chroma on max brightness is a bit less than 1V according to the PAL standard.

    Or - let's say I have another card (another manufacturer) with s-video in, where I know which pin does what, so if I measured resistances there, perhaps I should expect similar on the ATI card?
     
  4. sailorjoe

    Member

    Jun 4, 2013
    361
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    Option 2 is a Hail Mary pass. Different manufacturers design differently. There is likely some circuitry between the connector and the video chip, so just looking for continuity probably won't work.
    let's tackle this from the external connector side. Do a search on "video connector pinouts". Find one that matches what you have, and that should answer your original question.
     
  5. brontozaur

    Thread Starter New Member

    Dec 20, 2015
    11
    0
    That's the thing - it's some proprietary ATI breakout socket which packs all sorts of audio/video inputs/outputs. No pinouts on the net, it's quite rare and non-standard.

    Do you think the grounds on these tipes of circuits are shared?
    And if I tried to figure out the output pins first with a voltmeter, what should I use for external ground in order not to fry anything? some sort of battery?
    S-video PAL voltages can be found in documentation - they're around 700 mV on white screen output
     
  6. BReeves

    Member

    Nov 24, 2012
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    64
    I am pretty sure I have an older ATI All In Wonder, probably PCI out in the shop. The breakout cable is still with the card and may even have the documentation.
    Where are you located and what ya got to trade..

    Should add> Odds are pretty good the cable is the same, my memory is telling me it has a large multi pin connector with all sorts of pigtails for video/audio in/0ut. If you can wait a couple days I will dig it out and see if I can figure out what pins the S-video connector is hooked to.
     
    Last edited: Dec 22, 2015
  7. brontozaur

    Thread Starter New Member

    Dec 20, 2015
    11
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    The cable is like this: http://hothardware.com/reviews/ati-allinwonder-pci-express-x600-pro?page=2
    It has metal casing and attaches to the card with one screw.
    Do you have that one?
    I'm between Germany and Switzerland.
     
  8. sailorjoe

    Member

    Jun 4, 2013
    361
    63
    Looks like you've found a good source for information and maybe a cable. Here are some links that may be helpful with tracking down the signals. http://www.tomshardware.com/reviews/tft-connection,931-8.html
    https://en.m.wikipedia.org/wiki/Digital_Visual_Interface
    Are you sure these diagrams are not applicable to your connector?
    By the way, don't put any batteries into your measurements. The flat plate on the back edge of the circuit board should be a good ground for your voltmeter measurements.
     
  9. brontozaur

    Thread Starter New Member

    Dec 20, 2015
    11
    0
    nope, this is DVI, and mine is ATI proprietary crap which splices together video and audio ins/outs and even radio anthena input, all in one breakout socket. No pinouts on the web.
     
  10. BReeves

    Member

    Nov 24, 2012
    412
    64
    Sorry, not going to be much help. I found the ATI card and cable. It has a different connector for the video/audio than your card. It's 29 pins in a snap in connector. Best bet may be to give up on the ATI card and get a video capture card like a ViewCast Osprey. Check eBay, I bought four Osprey 210c's off eBay for $30.00 last year ($7.50 ea). It does just as good as the ATI at video capture and has both S-Video and composite inputs.
     
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