funny story. I have the exact same problem. But, I am pretty sure I know what happened. I was swapping displays (broke my old one, bought a new assembly, long story) and I must have hit something and shorted something out (it was off at the time w/ battery out though I swear) because now I have no wifi nor speakers. Is it possible that I hit a connector and I just need to reconnect it? (Yes, the wifi antennae are connected, unless they're broken) I've tried looking for anything loose, but I have no idea what I'm looking for, so I'm not able to find anything. It just happened tonight. If anybody wants to know more about my predicament (and maybe solve both our problems at once), I'll check back in the morning and do some more prodding.
If it means anything (not sure if it does) but I'm getting a new Left I/O board tomorrow because I may have sorta kinda accidentally bent (and broke) an inverter cable pin. whoops.