i've checked pulseaudio settings, there, in input tab, mic is unmuted and volume of mic is on 100%.
but when i opened alsamixer i found that i have 4 (or 5) mics and they are muted, when i activated them, i couldn't add their volume.
i thought that problem was in sound card driver. i mean, i have forgotten to enable some modules. but i recompiled kernel again, enabling all that related to sound, but it doesn't worked again.