My macbook is 3 yrs old. Last summer my magnetic power adapter stopped working, so I replaced it with a semi-used identical adapter. A little while later the battery died which I also replaced 3-4 months ago. About a week ago I started using external speakers to watch movies from the macbook which ultimately led to a problem I've read about on this forum before. basically my computer couldn't recognize the internal speakers after being disconnected and only showed the option of "external speakers" I followed the advice of some users by just plugging and unplugging the speakers a few times which seemed to do the trick and my sound was back. The only thing is that now the little "ding" sound that usually follows pressing the volume up or volume down buttons is gone. Soon after I started to have the same issue with the power adapter where the light would go out and I'd have to jiggle it in order to get a charge. After a while it just refused to take the charge at all, so I assumed the charger being semi-used to begin with, had run it's course. After spending $80 buying the brand-spanking new mag-safe adapter everything seemed to be fixed (with the exception of the volume "ding" sound) but after only one day of use the new adapter has completely stopped working. I'm now back to the old adapter, which has suddenly started working (kind of) again, but I've been sure to only charge it for a short amount of time and unplug everything afterwards. I'm assuming this is something to do with the Macbook now and not the adapters. Any ideas?