With no other options to resort to, I attempted to glue the speaker cable back down. .. I used super glue and was careful to make sure the metal connectors were well aligned. .. knock on wood, it seems to have worked. I guess if it ceases to be a sufficient fix, replacing the motherboard might be the next step, or maybe soldering the connectors back together? Try to avoid this in the first place by either leaving it connected or gently prying under the wires themselves to disconnect from the socket.

BE CAREFUL HERE- I was following these directions and inadvertently removed the speaker cable SOCKET from the motherboard, the directions were not clear enough on how to pry the cable off, as in other procedures I've read after the fact. If you pry up from under the wires you should be much safer and the cable end will release, leaving the socket still attached for you to plug it back into. Luckily, I was able to just glue the socket back down so that the metal connectors were in contact, and so far, my speaker does work. .. better than replacing the motherboard, although I guess that's the next step if this doesn't suffice. .. just be careful!

Omg I wish I had read the comments first, disconnecting the speaker cable is entirely unnecessary, and the directives don't give you enough guidance- I pried upwards and of course unknowingly disconnected the socket from the motherboard! Sh*t. Now trying to figure out how to remedy it, when it wasn't a problem to begin with. So frustrating to cause MORE damage because of an unnecessary step! Argh.