I know it's an old question, but I've gone through the FAQs on Ubuntu.com and can't find the solution.
Speakers work fine - ie if I go to System Settings > Sound, the tests sound. As soon as I plug in my headphones, it goes dead.
duncan@pliny:~$ lspci -v | grep -A7 -i "audio" 00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 04) Subsystem: Samsung Electronics Co Ltd Device c0b3 Flags: bus master, fast devsel, latency 0, IRQ 29 Memory at c0800000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel
duncan@pliny:~$ sudo aplay -l **** List of PLAYBACK Hardware Devices **** Home directory /home/duncan not ours. card 0: PCH [HDA Intel PCH], device 0: ALC269VC Analog [ALC269VC Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0] Subdevices: 1/1 Subdevice #0: subdevice #0
And my alsamixer:
Headphones plugged in:
It seems there is sound from headphones - it's just unbelieveably faint...