I am running Ubuntu 14.04 on a Dell Inspiron, everything has been working fine for about 18 months. Suddenly this morning, there is a loud and repetitive clicking sound coming from the headphones and/or laptop speakers. This happens as soon as the laptop boots up and continues until the laptop powers down.
I can get it to stop by selecting "Microphone" as an input source, instead of "Internal Microphone" or "Headset Microphone." Muting the microphones or sliding their volume down has no effect on the clicking. Sound is coming out of the laptop speakers normally most of the time, sometimes the clicking kills the speaker audio. Audio is no longer coming from the headphones.
The "Microphone" appears on the list of input devices that are created when I plug any 3.5mm jack into the headphone port. Even plugging the headphone cable without headphones does this. Audio from the laptop speakers works fine when I select "Speaker" as output, but audio from the headphones is dead even when I select "Headphones" as output. How do I get audio to come out of the headphones properly again? This has worked for 18 months.
I thought uninstalling and reinstalling alsa-base and pulseaudio may fix this. Not only did it not fix my sound issue, it buggered up the system settings app. Reinstalling ubuntu-desktop has restored the system settings app, but the sound issue is still there. Any ideas?
Just ran the onbaord diagnostics, all tests passed, including the speaker test.
UPDATE #4: I played around with just about everything in alsamixer, couldn't find anything obviously wrong, but the problem seems to have gone away. The clicking is gone both with and without headphones plugged in, but the background hiss is louder than it used to be. Maybe it's an intermittent hardware problem?
UPDATE #5: The loud hiss is only present when the laptop is plugged in, it disappears when the laptop is running off the battery.
UPDATE #6: The loud hiss was even louder this morning, and I could even pickup somekind of broadcast, sounds like a TV or radio signal. No, I couldn't tell which channel.
UPDATE #7: After a couple of reboots, everything is back to normal, even the loud hiss. Is my laptop haunted?
Update #8: After about 10 days of running normally, the loud hiss is back. Running the laptop off the battery deselects the headphones as output. That normal?
alsa-utils did not fix the problem (again), but instead caused sound settings to no longer list audio hardware.