bose ipod portable sounddock won't turn on

My Bose portable Sounddock wouldn't turn on this morning. I unplugged it, plugged it in again, didn't hear the bloo-bloop sound. It wouldn't play music from my docked iphone.

I removed the battery (use a coin to twist the spot on the back) and plugged it in. It worked. Several minutes later, I reconnected the battery. Good as new.