hdmi audio stops 10 minutes after boot, repeatable

Black’s hdmi connected to an hdmi-2-av external powered device connected to a power amplifier connected to speakers.

In other words: Black → hdmi-2-av → amplifier → speakers

Audio is tested with ‘speaker-test’. Speaker-test is started soon after reboot. “Right channel…left channel…right channel…left channel…”

The test tone is heard as expected until exactly 10 minutes after reboot.

The only external sign of a problem is no more sound. There are no log messages in dmesg or /var/log/*. speaker-test continues to run, sending text to stdout.

Any hypotheses?

How can I debug?


Other info:

The faulty black runs this linux:

root@beaglebone:~# uname -a
Linux beaglebone 4.4.30-ti-r64 #1 SMP Fri Nov 4 21:23:33 UTC 2016 armv7l GNU/Linux

root@beaglebone:~# cat /etc/debian_version

I have a second black and it does not have audio problem. It was purchased several months earlier than the above. It is running factory provided angstrom. I don’t have it handy to obtain the ‘uname -a’ output.

Sorry for the double post. Please ignore this one. I didn’t find my first attempt and thought it was lost.

Any reason why you can’t look at the post you made yesterday ?