No Sound from Mother board, only Front panel

[breitinger]

I have no sound on new build. It recognizes when something is plugged into jacks though. Most of the time... Sometimes I'll plug in and it'll say "You are seeing a blank page because there is no audio devices plugged in the system. To activate GUI, please plug an audio device into the system." I have it all plugged into motherboard. My brother said that since I have a video card it is overriding the motherboard or something.
Build:
Asus Z97 Sabertooth Mark 2 - MB
Sapphire R9 280x Dual-X -GPU
2 1866 4GB, 1 1600 4GB, 1 1866 8GB -RAM DDR3
intel i5 4690k

No sound, Realtek driver is up to date. Also, I currently have DVI plugged into monitor, but when I tried HDMI it didn't work. I want to HDMI because my monitor has audio ports, but the screen was blank. Please help.I have Windows 8.1.. front panel works sometimes if I disable High Definition Audio Device in Device Manager. However, when it is on nothing works. When I plug into the back Realtek pops up and shows me where a device has plugged into and is always correct, but does not actually detect. (EX: I plug a device into line-in in the back, Realtek opens up asks "what device did you plug in? and offers a list of possibilities with the correct one pre-selected. I hit OK and it offers me to change playback volume, but no sound comes out.
Also, I went to bios and made sure HD Audio was turned on.When something is plugged into the back, there is no playback devices.

 

[Markkk]

According to Specs from web site as follows;

Realtek® ALC1150 8-Channel High Definition Audio CODEC
- Supports : Jack-detection, Multi-streaming, Front Panel Jack-retasking
- High quality 112 dB SNR stereo playback output (Line-out at rear) and 104 dB SNR recording input (Line-in)
Audio Feature :
- Absolute Pitch 192kHz/ 24-bit True BD Lossless Sound
- Optical S/PDIF out port(s) at back panel
- BD Audio Layer Content Protection
- Audio Shielding: Ensures precision analog/digital separation and greatly reduced multi-lateral interference
- Dedicated audio PCB layers: Separate layers for left and right channels to guard the quality of the sensitive audio signals
- Audio amplifier: Provides the highest-quality sound for headphone and speakers
- Unique de-pop circuit: Reduces start-up popping noise to audio outputs

### This Part - Refer Motherboard Manual
- Jack-detection, Multi-streaming, Front Panel Jack-retasking
As this may mean when Front Audio is connected the Back wont work

Personally I find this Auto Jack Sensing Very annoying in most cases - as you are now experiencing.
You Can usually manually set these options in the Software provided - You Need to Also Install the Sound software as it will give a much better array of control - and allow Manual configuration of what each sound plug is assigned to - and hopefully allow you to turn off "Auto screw up my sound" options

You Will need to Check what the OS has Selected as Default Sound
What the each Program your Using has defaulted to as Sound