I took an ebay gamble on an LG xboom pn5 speaker which was listed as having battery issues (turning on then off).

I got it earlier today and concluded it's in a demo mode because of the following:
  • When it's plugged in, it'll turn on and the power button will not turn it off
  • Battery is healthy, reading 4.2v and not swollen, charges according to the xboom app
  • the play/pause and volume buttons don't work
  • You can pair to it and play music fine, as long as it's connected to power
  • The bluetooth connection is disconnected after 5 seconds of audio pausing
  • The DTS setting is defaulted
...