What is the front panel audio jack?
On most modern PC ATX case, provisions for microphone and audio jacks, as well as USB and Firewire ports at the front are common. This makes it more convenient to plug a USB drive or headphones instead of connecting it at the back where traditionally the jacks and ports are located.
The front panel audio jack has the same function as the one at the back of the case. It lets you connect speakers or headphones. Usually this is the green-colored jack.
There are cases where the front panel audio jack will not work on a Linux operating system. There are many reasons why this happens. It happened to me not too long ago when I switched from a USB headphone to one with a stereo mini plug.
My machine is not branded. I just selected the parts individually and had it assembled at the store. This was one of the reasons why it didn’t work. While the 2 USB ports at the front were working fine, I found out that the front microphone and audio jacks were not connected properly by the technicians at the store. Lucky for me I’m a bit familiar with the internals of a PC, so with the motherboard manual I just followed the instructions and connected the colored wires properly.
Booting to my Ubuntu Lucid Lynx later, there was still no sound coming out from my Sony XDR-MB500 Extra Bass headphones. I tweaked the sound configuration, installing additional ALSA and PulseAudio tools in an effort to make it work. Still no sound. This was my cue to Google the problem.
The solution I found was to explicitly tell ALSA what sound card model you are using. First I had to find out my sound card model. Below is a link to a list of the most common models.
http://www.kernel.org/doc/Documentation/sound/alsa/HD-Audio-Models.txt
My sound card model is an ALC888. Since my PC is unbranded I chose “auto.” (Actually my motherboard is Intel. However a generic Intel model is not in the list.)
The next step was to add the line below to the ALSA configuration file at /etc/modprobe.d/alsa-base.conf. Note that MODEL should be replaced with your sound card model.
options snd-hda-intel model=MODEL
In my case it looked like this:
options snd-hda-intel model=auto
It is best to add this line at the end of the alsa-base.conf file. Since this is a system file I had to use sudo to edit and save the changes. You can use either of the 2 commands below.
terminal: sudo nano /etc/modprobe.d/alsa-base.conf
GUI: ALT + F2 (for the run command dialog box), then type in – gksudo gedit /etc/modprobe.d/alsa-base.conf
Once all the necessary steps above were done, I proceeded to reboot my computer for the changes to take effect. Optionally you can just reload ALSA. On a terminal, use the command below to reload.
terminal: sudo alsa force-reload
If you are having the same problems as I have described above, I suggest you also read the following documentation from Ubuntu Wiki. Even if you’re not using Ubuntu or any of its variants, it might still be helpful.
https://wiki.ubuntu.com/DebuggingSoundProblems
https://help.ubuntu.com/community/HdaIntelSoundHowto