I think you might be best served to use
task-pulseaudio-remove to uninstall PA after turning it off in PCC .... if you had installed PA using the
task-pulseaudio meta package to install it in the first place.
Reboot, and ignoring the state of the sound system, install it again using
task-pulseaudio. In addition ensure that
pavucontrol is installed.
Enable PA through PCC and immediately reboot.
When rebooted, launch pavucontrol and in the
Configuration tab see what sound cards are available to you.
Your HDMI should be there in addition to the internal sound card.
Play an audio file and go to the playback tab on pavucontrol ...... there you should be able to choose through which sound card to play streams from whatever application you are using.
The above scheme has not failed here on some 5 different PCs and two laptops.
Don't assume that any part of the above sequence has been done properly up to now.
Do it again as above .... it should work properly.
If the above doesn't work then maybe referencing this thread could help ...... bearing in mind that its content may be somewhat out of date by now
http://www.pclinuxos.com/forum/index.php/topic,83740.0.html