Ubuntu 7.10/Issues/Built In Digital Mic Does Not Work
From DellLinuxWiki
Description: Built-in digital microphone (next to webcam on top of screen) does not work.
Systems Affected: Inspiron 1420n, 1525n, XPS M1330n.
Impact: Can't record audio.
Fix: Download Dell's custom linux-backports-modules (l-b-m) package linux-backports-modules-2.6.22-14-generic_2.6.22-14.50_i386.deb. This custom l-b-m is not available on any of the Ubuntu repositories, it is only available here.
To install, run:
$ sudo dpkg -i linux-backports-modules-2.6.22-14-generic_2.6.22-14.50_i386.deb
And reboot your system:
$ sudo reboot
Finally, make sure that the alsamixer setting Digital Input Source is set to Digital Mic 1.
For Inspiron 1420n and 1525n ONLY: Because this l-b-m package updates the ALSA code, if your system has the HSF modem driver v7.60.00.18oem installed, it will no longer work with this custom l-b-m package. You will need to download a custom HSF modem driver:
Remove old HSF modem driver:
$ sudo dpkg -r hsfmodem
Next, download the custom HSF modem driver hsfmodem_7.68.00.06tst1oem-1_i386.deb and install it:
$ sudo dpkg -i hsfmodem_7.68.00.06tst1oem-1_i386.deb
And reboot your system again:
$ sudo reboot
This driver is also available in rpm and tarball format here. These packages were not tested and/or qualified and are provided as-is.
