SPDIF Ground Pin for HDMI enable

[cbeere]

My Mobo = GA-X58A-UD3R  (2)
My graphic card =  MSI  N250GTS

My question,
I am trying to hook up SPDIF to enable full audio on HDMI dongle for DVI to HDMI convert.  The graphic spec says hook orange
cable from graphic to SPDIF on mobo,  connect black lead to mobo ground.
How do I know which pin on my Mobo and graphic card are are ground, and which are signal?
There is a number 1 next to one of the 2 pins for the SPDIF on the mobo.

Confusingly there is another SPDIF 3 pin port on the mobo, I am not sure if this is the one to connect grapic link to or
if it is the 2 pin SPDIF  (I think it is the 2 pin,).

Is there an easy way to test to see which is signal and which is ground?
The graphic card spec says to beware, as wrong connection can damage graphic card.  Any help greatly appreciated.

thanks
clive

[absic]

Hi there,

The 3 PIN SPDIF is for input to the on-board sound whilst the 2 Pin SPDIF is for output to your Graphic Card or another expansion card.

If you look at the 2 pin SPIDF the pin nearest the CPU is PIN 1 and this is where you need to connect the Orange lead. Pin 2, which is the pin directly below PIN 1, is for the Black Ground lead.