I think I just killed my laptop. I accidentally connected a 9v rated charger to the power lines of a protoboard. How did that "kill" Luna, my laptop? You might wonder... [1/4]

Well, you see, the 'board was connected to a USB to Serial bridge which in turn was plugged in to the laptop. As soon as I touched the other 'board power line with the second lead, Luna shut off. [2/4]