Totally Unresponsive - SMC Dead?
MD322LL/A (Late 2011 MBP 8,2) running El Cap.
Was using it in the Anchorage airport. Went outside to smoke. Came back in. Laptop had turned itself off while we were outside, which seemed odd but whatever.
Used it for a few more hours, then traveled from the one airport to another, which entailed two heated bus rides along with maybe a total of an hour outside.
Got to the other airport and the thing was totally dead. It won't boot, there's no pulsing status indicator light, it won't report battery level (which was full when I left the airport) via the little button on the side, and the light on the magsafe won't turn on when attached. I've never seen a laptop so dead.
I'm thinking the temperature back-and-forth in Anchorage thrashed something, and given that the SMC controls the power button, SIL, battery management, and battery indicator light, it is my prime suspect.
I read somewhere (damned if I can find it again, though) that the SMC is powered by a battery on the logic board. And I know that cold is rough on batteries. My hope is that it's a common button cell that can be easily replaced. But I could be on the totally wrong track here.
Is there any hope of repairing this, or is it new logic board i.e. new mac time?
Edit: FWIW, I've tried SMC reset via the standard procedure for macbooks with "non-removable" batteries (shift-ctrl-option-power, as well as the older procedure (power button for 10 sec) by opening up the bottom and disconnecting the battery. No effect. Also went through the motions of a PRAM reset, just for kicks. No change.
Magsafe charger is known to be good. Main battery status is unknown, but I'd think that it could boot via magsafe power regardless.
Update: I tried disconnecting the battery, then booting on magsafe power, to check if a faulty battery was interrupting the power circuit or whatever. No change.
Tried bypassing the power button by shorting the solder pads, both with keyboard attached and detached. No change.