crazy stuff just happened. I was watching youtube vids on my dv6700 through my hdmi and my power cord tip just melted and burnt my hand! Both my cord and battery are newer. now my computer only holds a 30 min charge... should i not keep it plugged in? what just happened? i unplugged it and let it rest and seems ok.(other than the fact it only plugs in half way) its a old computer with little value obviously but its my internet/school work computer.