I think I read somewhere in the manual you have to use the front audio connection on the case front panel in combination with the mb connections in the back panel to use 5.1/7.1 if not using the optical output.Edit: You can see it on page 35 in the m...
About Q-code 15: It is also mentioned several times in the manual. It's no error, it's the mb doing it's "memory training" thing, and takes it's time depending on the ammount of ram installed. Just let it do it's thing and you're good.
If you had taken your time to read the motherboard manual you'd know what's going on, but pretty sure you didn't. Those are no error codes. By default bios is set to show cpu-temps after successful boot.
