Why can't I change my volume?

I just purchased a used 8gb iPod Touch 2nd gen, and for some reason my volume stays on one level. I am not able to adjust it at all. Can anyone help me try and figure out what's going on and how to fix it? Please and thanks!

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0