Red Hat Bugzilla – Bug 483864
System restart causes loud popping noise.
Last modified: 2009-02-04 19:48:20 EST
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:18.104.22.168) Gecko/2008121622 Fedora/3.0.5-1.fc10 Firefox/3.0.5
When restarting the computer, there is an extremely loud popping noise (Capacitor discharging), enough that I leave the room if I select restart on accident to avoid it. The volume has no effect on the level of the pop. Starting up and shutting down windows XP and Fedora both give a soft pop. Windows restart gives soft pop, so the problem is in Linux. Sound card is Sound Blaster Audigy 2 connected to a powered sound system with subwoofer.
Steps to Reproduce:
1. Select restart from the shutdown menu.
2. Allow computer to reboot.
Very loud pop emitted from speakers.
Quieter pop, similar to when shutting down.
Used to have loud pop when shutting down in Fedora Core 6, but that was fixed sometime during that release. The loud pop on reboot has existed in all versions of Fedora since Fedora Core 6. There are three workarounds I know of:
1. Use shutdown and manually power cycle computer. Undesirable since it hits the computer with a power cycle and causes my fans to spin up unless I let the system cool for a minute.
2. Climb under desk and turn off speaker system (Power switch on powered subwoofer. Unable to relocate). Undesirable.
3. -Open gnome sound mixer.
-Uncheck Audigy Analog/Digital Output Jack option.
-Restart system (No pop).
-Open gnome sound mixer.
-Check Audigy Analog/Digital Output Jack option to restore audio.
My smolt profile can be seen here: http://www.smolts.org/client/show/?uuid=pub_1fb55c4d-ae7e-4fac-b455-1e460f50ced5
You may add a line 'amixer set "Audigy Analog/Digital Output" off' to /etc/init.d/halt script bellow Save mixer settings block.
That line failed in my case with the error message
amixer: Unable to find simple control 'Audigy Analog/Digital Output',0
I mucked around with amixer for an hour and finally figured out that I needed to specify my card number in the command. The relevant section of my halt file now looks like
# Save mixer settings, here for lack of a better place.
if [ -s /etc/alsa/alsactl.conf -a -x /sbin/alsactl ]; then
action $"Saving mixer settings" /sbin/alsactl -E ALSA_CONFIG_PATH=/etc/alsa/alsactl.conf --ignore store
#Turn off speaker output to avoid nasty pop.
amixer -c 0 set 'Audigy Analog/Digital Output Jack' off
Work's perfectly, my problem is fixed. Thank you.