Sound is gone and Back-up drive is missing

[hunt_mat]

Hi,

Approximately 2 weeks ago the sound went on my system, I think that this was after an update but I can't be sure. The only thing where I can hear sound is if I play movies with SMplayer, then the sound is fine, so I know it's not a hardware problem but a software problem. I tried changing the settings to use smplayer for the media but that didn't work. (funnily the sound doesn't work in kmplayer). Any suggestions?

Secondly and more worryingly, I go to dolphin and I can't see my 1 tb back up drive with all my important work on it, I saw it and even viewed it last night but it wasn't anywhere to be seen this morning. What can I do so this doesn't happen again? I recently cleaned my computer and I was working like a dream.

Recently my computer has been slowing down when setting up the LVM, is this meant to happen?