H170i-plus D3 motherboard SPDIF out

[AgentCoop]

Hi, hoping someone can help me.
I have Asus H170I-plus D3 mini-ITX motherboard and I'm trying to get the onboard optical output to work (to get digital audio to my old receiver that doesn't have HDMI...).
The problem is that when I connect the optical cable, there is no red light and my Linux Mint doesn't see the SPDIF output.
I have selected SPDIF output in the BIOS I think (where it gives you an option to select either HDMI or SPDIF as output), but no luck.
So having no red light coming out of that port means there is no signal and it's a hardware issue?
Everything else on the motherboard works fine, including Ethernet and other ports.

Thank you!
Anton.

 

[Lutfij]

Is the device found when you follow through with hardinfo? Have you manged to install another OS to verify that the devices are in working order? If it isn't then the motherboard qualifies for an RMA(provide the device does not pop up in a Windows environment/platform).

Have you made sure your BIOS is up to date?
(look at others in the drop down menu).