I have an Asus EEE PC 1225B with fresh Lubuntu 12.04. And no sound. It doesn't seem to be some common problem, so I have to make some research what's up. I tried running alsamixer, so I know I have Realtek ALC269VB with nothing muted unexpectedly. What can I do next to identify and solve the problem?

Additional info:

alsamixer shows two cards: HD-Audio Generic and HDA ATI-SB (Realtek ALC269VB); the first one is muted.

~$ aplay
ALSA lib pcm_dmix.c:1018:(snd_pcm_dmix_open) unable to open slave
aplay: main:682: blad otwierania audio: Nie ma takiego pliku ani katalogu

The Polish part can be translated as "error opening audio: There is no such file or directory".

~$ sudo lspci -v | grep -A7 -i "audio"
00:01.1 Audio device: Advanced Micro Devices [AMD] nee ATI Wrestler HDMI Audio [Radeon HD 6250/6310]
    Subsystem: ASUSTeK Computer Inc. Device 103b
    Flags: bus master, fast devsel, latency 0, IRQ 44
    Memory at feb44000 (32-bit, non-prefetchable) [size=16K]
    Capabilities: [50] Power Management version 3
    Capabilities: [58] Express Root Complex Integrated Endpoint, MSI 00
    Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
    Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
--
00:14.2 Audio device: Advanced Micro Devices [AMD] nee ATI SBx00 Azalia (Intel HDA) (rev 40)
    Subsystem: ASUSTeK Computer Inc. Device 103b
    Flags: bus master, slow devsel, latency 32, IRQ 16
    Memory at feb40000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: [50] Power Management version 2
    Kernel driver in use: snd_hda_intel
    Kernel modules: snd-hda-intel