1 Reply Latest reply on Nov 8, 2010 10:23 AM by stardotc

    No Audio with PC to TV via DVItoHDMI + 3.5mm Audio

    stardotc

      Objective

      http://oi53.tinypic.com/mb0k6p.jpg

       

      Problem

      Video is fine but no Audio.

       

      Setup

      Motherboard: Intel BOXDG41MJ

      CPU: Intel E5400

      RAM: Mushkin 2x2GB PC2 6400

      OS: Win 7 Ultimate 64

      TV: LG 32lh40

       

      Drivers All from Intel site

      Chipset - 9.1.2.1008

      Audio - 6196

      Video - 15.17.10.2189

      BIOS - 0007

       

      Some stuff I tried/noticed

      - Unplugging HDMI produces sound. Plugging it back in, makes the sound go away again.

      - Plugged in my Macbook (Intel GMA 950 chipset) with exact same wires (DVI + Audio) and got Video and Audio to work.

      - Talked to LG people. They blame it on PC.

      - Talked to Intel people. They blame it on TV.

       

      Here's what I think is happening ... For some reason LG TV sees an AUDIO signal over HDMI and does not switch to RGB/DVI IN input. Meaning, G41 Chipset is sending something that makes LG believe there's AUDIO on the line.

       

      There're some tutorials that advise overwriting EDID/CEA data to disable CEA portion (which carries Audio settings among other things). I've tried that and it didn't do much.

       

      I find it interesting that the older Intel GMA 950 chipset is properly handling the data where the newer G41 chipset is screwing it up somehow. Although this is most likely the driver/OS/something software related.

       

      I'm definitely running out of ideas and I googling didn't produce anything constructive. Any ideas/suggestions?

        • 1. Re: No Audio with PC to TV via DVItoHDMI + 3.5mm Audio
          stardotc

          Here's what I gathered from another chat with Intel people ...

           

          G41 chipset actually supports sending Audio data over DVI/HDMI. However the motherboard lacks controller that forces the sound card to send its data to the chipset. Thus G41 just blindly sends nothingness over DVI/HDMI. TV thinks there's actually Audio Data on the channel and plays it ... In reality, there's nothing there and thus sound does not work.

           

          Concerning older GMA 950 chipset ...
          The Express chipset does not have a native HDMI support and does not care about Audio and only sends Video signal over DVI/HDMI. Since there's no Audio data over HDMI, TV automatically looks for an Audio input on any supported channel (in my case it's RGB/DVI IN) and if there's something there, it plays it.

           

          Which is why my MacBook is able to take advantage using this setup and G41 based PC is not.

           

          I can't even get a cheap HDMI card due to lack of PCI-E ... the only PCI slot is occupied as well. Oh well, no luck to be had.

           

          Hope this provides some answers/closure to people Googling this stuff.

           

          P.S. Anyone know how to hack G41 chipset and tell it to STFU with its Audio portion?