It's been left plugged in for several days and exhibits the same behavior (and consistently loses date/time settings, which is pretty much a guaranteed sign of PRAM battery failure). Considering how old the Kanga is I'm not surprised at all that it needs a new one. I located a new replacement online for $12 and am going to put it in when I replace the keyboard. If that solves the power issues I'll have ended up with a reliable PBG3 for less than $50 invested.