no sound on HP dv9000 laptop

check the settings for your hardware or best reinstall your driver

Howdy Mike-d. here,
Does any of this help?
https://answers.launchpad.net/ubuntu/+question/23897
It is what I end up using most of the time.
Since it is Kubuntu it may be a little different, ask for more info , if you need more info.

Disclaimer: I mostly just file bug reports and crash reports.
I use Ubuntu so the location and dialog boxes may differ a bit but it's probably the same idea.
"Potential Lock-up Warning"
 I'm going to tell you how to pick which sound equipment you can use, but I have seen this lock-up computers before, so make sure you save or close whatever your working on and what don't want to lose in case of lock-up, I'm not talking about file erasing or anything that bad, other than that, it usually just requires you to turn -off computer and turn it on again.
o.k. to choose the built in hard ware and drivers:
Left click on System-> Preferences->Sound
Sound Preferences Window will open.
under the devices tab, Sound events, sound playback there will be the hardware detect to choose from.
you can click on the auto detect, and an annoying sound may come out, good if you had no sound before, sometimes it kind of scratchy,
you can work your way down the line on the different items, see, or hear what sounds better and go with that, it usually remembers whatever you choose.
make sure you have speakers plugged into the right place on the computer, and that they are powered either by the computer, or batteries, of electricity, or whatever.
sound capture stuff you may leave alone unless you going to record sound or incoming signals, because you won't really hear anything unless you have an active sound signal going through, and it sometimes locks up a system. I usually don't hear much or any sound from the built-in PC Speaker, or Piezo Buzzers some computers have.
good luck.
Some else chime in if your sound's working and you got a better way.
Mike-d. out

What worked for me with my HP Pavilion DV9700 laptop, and also for a friend with a Dell laptop with the same problem, was to open terminal and type the following line. You'll be asked for your root password. After this finishes installing, reboot your computer, and you should have sound. Good luck!

sudo apt-get install linux-backports-modules-generic

Frank