I'll suggest starting with a reset, with battery out and laptop unplugged, press and hold the power button for ~30 seconds, put battery back in, plug in power adapter, see where you get.
If there was a power event (brown-out, surge...) a polyfuse may have "blown" (polyfuses are nice because they reset themselves) and in that case simply waiting and trying again "fixes" things (wait time can vary but shouldn't be more than a few hours)