Edited by jotapesse at 2016-3-7 16:41

Have you selected the "Headphones" output port in the Control Panel > Sound > Advanced > Output port options?

Yes of course. it is automatic btw, right? already tried this and this too.

Edited by jotapesse at 2016-3-8 01:15

I can confirm that there are issues with it. It also does not work for me. In my case I'm using AMD/ATI audio with HDMI speakers. Also an onboard Analog audio card. Is this your configuration also? In my case I have 3 issues:

Problem:
1. Output devices defaults to HDMI Audio Out (speakers work ok) but Analog Stereo Output is disabled;
2. Built-in Audio profile in Pulseaudio automatically changes from 'Analog Stereo Output' to 'Digital Stereo (IEC958) Output' if heaphones/line-out disconnected;
3. If the above are changed, the current audio playing application does not update the device that it plays output to;

Control Center Sound does not allow to solve the above. I had to install pulseaudio utilities to activate it. You may try:

Solution: (Workaround) To solve the above 3 issues I had to, respectively:

1. Start application 'PulseAudio Preferences' or 'paprefs' in terminal and manually activate the 'virtual output device' for 'Simultaneous Output' - so that it can play simultaenously HDMI speakers and Analog line-out/headphones, then restart pulseaudio in terminal:
This 'Simultaneous Output Device' will now be available in Control Center Sound, but don't change it.

2. Start application 'PulseAudio Volume Control' or 'pavucontrol' in terminal and:
   2.1. Tab 'Configuration': Verifiy if on 'Built-in Audio Profile' it is selected 'Analog Stereo Output' (if not select it);
   2.2. Tab 'Output Devices': Verify that 'Simultaneous Output Device' is avalable (Show All Devices) and click 'Set it as fallback', or, alternatively, in Control Center Sound select the new 'Simultaneous Output Device' and the previous headphone output port will disapear. Control Center Sound and Dock Sound Volume will now use 'Simultaneous Output Device';

3. Still in 'PulseAudio Volume Control' Tab 'Playback': Verify if you have any apllication playing audio currently. If you have it's probably playing to the previous default 'HDMI Audio Out'. Select 'Simultaneous Output Device' on every application listed. You should the hear also audio from both HDMI speakers and also heaphones (if connected);
   3.1. Tab 'Output Devices': Adjust volume levels properly (with an audio source/application playing);

Please take notice that, in my case, whenever I disconnect the headphones the issue 2. Built-in Audio profile in Pulseaudio automatically changes from 'Analog Stereo Output' to 'Digital Stereo (IEC958) Output' takes place and the 'Analog Stereo Output' and heaphones output disapears from Control Center Sound so we have to repeat the whole process again.

If you don't want simultaneously output, then select the output device accordingly in Tab 'Output Devices'. Hope this helps you. Not sure what causes this, possibly a driver issue, but whatever the case the current Deepin Control Center Sound is very limited in its options and doesn't help to solve it.

Request: Deepin team could you please upgrade Control Center Sound so that it can cope with this issues and allow us to solve it without using pulseaudio utils? Thank you.

This is a know issue, and it seems a fix is to be expected for upcoming Deepin 15.2 version. Meanwhile the above workaround will help.

wow. thanks for the quick help

You're welcome. You got lucky. :-) I had the same issue.