Broken Speaker part
My 700m has the same problem. The wires are cleanly cut where they enter the hinge, so presumably the speaker wire shifted and was guillotined by the screen hinge closing. The laptop is long out of warranty. Dell wanted $170 just to take a look, so I opened it up.
There's just enough wire left at the speaker, about 0.5", to strip. The replacement will need to be real thin though to fit through the hinge.
I was able to find one company, PChub, listing this part as "Dell Inspiron 700m Speaker Set", part# 4014J1, used for $15, but they are currently out of stock:http://www.pchub.com/uph/laptop/77-3...eaker-Set.html