Fixing a suddenly-unavailable MacBook battery (aka “that was odd”)

So, I’m sitting on the couch this afternoon, surfing the internets on my (unplugged) mid-2007 MacBook, when suddenly, the computer shuts off.

Thinking I’d failed to notice the low battery warning, I plugged in and restarted, only to find that:

  • The battery indicator was suddenly showing “no battery available”
  • The fan was running full-out, despite zero processor load
  • All of the temperature sensors except for the hard drive’s had disappeared from StatPro

I zapped my PRAM, ran the Apple Hardware Diagnostic from my original boot disc, no dice.  Swapped in a known-good battery from my wife’s laptop.  Still nothing.

Then I tried zapping the SMC, by removing AC adapter and battery, holding power button for five seconds, then reinstalling battery, reattaching AC adapter and restarting.

That did the trick.

That was odd.