Currently Being ModeratedDec 28, 2012 12:23 PM (in response to Neboe)
See if resetting the SMC helps
Shut down the computer.
Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
Release all the keys and the power button at the same time.
Press the power button to turn on the computer.
Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.
Currently Being ModeratedDec 29, 2012 7:59 AM (in response to Mike Sombrio)
This sort of helped. Here is what happened:
Upon the first boot after resetting the SMC, the MacBook indicated there was "no WiFi hardware installed."
Shut down the MacBook and waited 15 seconds then started - it recognized the WiFi hardware and indicated a connection to my local network, however none of the local devices could be found and the internet was not connected.
Restarted the MacBook to the same results as the previuos shut down/start up.
Shut down the MacBook and waited for 15-30 seconds. Upon pressing the power button only the indicator LED on the lower right side of the body illuminated solid and nothing else happened.
I had to then press and hold the power button for 3-5 seconds for the LED to go out.
I pressed the power button and the MacBook started (very slowly). I gave it a few moments after the desktop appeared and the bars appropriately populated (WiFi indicator on the top bar looking good). Internet and local devices connected and no fan . . . yet.
My confidence is low, it's only be about 5 minutes, but will post again with an update . . .
Currently Being ModeratedJan 2, 2013 6:51 AM (in response to Neboe)
OK so after a couple days of medium use, I have found that when connected to the magsafe power adapter, the MacBook is stable and back to normal. However when it's running on battery power it's as bad or worse than it was before I reset the SMC.
Is there anything I can do?
Currently Being ModeratedJan 2, 2013 8:39 AM (in response to Neboe)
I would reset the SMC again. Sometimes it takes more than once. I would also boot into safe mode and see if the problem persists http://support.apple.com/kb/HT1564
Currently Being ModeratedJan 3, 2013 7:49 AM (in response to Mike Sombrio)
Unfortunately all the same problems are persisting . . . I'm backing up to an external drive now.