Originally Posted by jpterj
Two of the wires are SPDIF+ and SPDIF- while the third wire is 5V+. If you have any documentation on the motherboard you should be able to find the SPDIF+ and SPDIF-. These are the ones that shall be connected to the 9400GT.
The motherboard is a FIC P4M 915PD, for which is impossible to find documentation. Anyway, I tried all combinations and never got sound. Finally, I managed to edit my EDID and disable the extension block, so having back the analog sound through the tv.
If it is possible to disable the "feature" which enables the signal that forces the tv to ignore the analog inputs by editing the EDID, why not add it as a driver option?