I was using my MBP when suddenly the charger light turned off and the entire computer turned off. I tried unplugging and replugging the charger to no avail. I was able to restart my MBP and it was fine. At this point, it was still unplugged from the outlet. Tried plugging it back in to no avail. Grabbed my old MB charger and it worked. What happened? Charger short circuited or something?