Thanks. I note an AD1886 hardware audio codec in your Compaq Presario 2715EA, running a 32-bit openSUSE-11.2 with the 2.6.31.12-0.1-default kernel and the stock 1.0.20/1.0.21 version of the alsa sound driver.
Your mixer settings look ok. Possibly you could move them a bit higher (master mono from 71 to 95%) but with overall Master at 100% and PCM at 97% it looks fine.
I do not know why you are experiencing this.
You could try install the latest alsa. There is guidance here Alsa-update - openSUSE , except rather than use the zypper commands proposed in that guide, I recommend you add the repos, install from YaST (not from zypper) and then remove the repos. Then restart and test.
Now if that does not work …
The HD-Audio.txt file for 1.0.21a of alsa has this to say:
Speaker and Headphone Output
One of the most frequent (and obvious) bugs with HD-audio is the silent output from either or both of a built-in speaker and a headphone jack. In general, you should try a headphone output at first. A speaker output often requires more additional controls like the external amplifier bits. Thus a headphone output has a slightly better chance.
Before making a bug report, double-check whether the mixer is set up correctly. The recent version of snd-hda-intel driver provides mostly "Master" volume control as well as "Front" volume (where Front indicates the front-channels). In addition, there can be individual "Headphone" and "Speaker" controls.
Ditto for the speaker output. There can be "External Amplifier" switch on some codecs. Turn on this if present.
Another related problem is the automatic mute of speaker output by headphone plugging. This feature is implemented in most cases, but not on every preset model or codec-support code.
You could check the content of the dmesg output after a fresh reboot via “dmesg > dmesgoutput.txt” (as a regular user in /home/yourusername ) and then look at dmesgoutput.txt in a text edit. … but I don’t think in this case it would give me anything that I would understand.
I recommend you write a bug report on openSUSE-11.2. Guidance is here: Submitting Bug Reports - openSUSE
When submitting the bug report, write it against component “sound”. You need to attach the diagnostic script output to the bug report. So run it via:
/usr/sbin/alsa-info.sh --no-upload
and attach the file /tmp/alsa-info.txt to the bug report. Do not bother referencing this thread as the alsa developer will refuse to read it. Instead include all relevant information in your bug report.
The person who will action the bug report is an alsa developer (in addition to being an openSUSE sound packager) and if anyone can sort this, they can.