MacBook Pro 13 in. (Mid 2012) Running Mavericks 8 GB RAM (installed myself) Ever since I updated to Mavericks, my computer has gone into a hibernation mode (like when the battery becomes too low to leave the computer running) every time I leave the computer charging overnight. It does not do this if an external device (iPod, hard drive) is plugged in. Fortunately, this has not been a problem: I just let the computer reboot and everything works as if it had just gone to sleep. Last night, I was using my computer like normally, shut the lid, expecting it to be in its hibernation mode in the morning. My brother removed the charger in the morning and began charging his own computer, and the usual awakening-from-hibernation sound went off (it does this even when closed). I returned to turn on my computer but alas, it did not do as such. Instead the screen remained black, the charger did not light up at all, and even the battery level showed not even a single green dot. I have removed and reconnected the connector from the battery to the logic board, but to no avail. I recall that my battery has just passed 500 charge cycles, but it is designed for 1000. Thank you so much for any help you offer.