hi guys,
i have a story to share, to protect your hardware.
In last event there was all devices switched in one electric line. BE AWARE OF IT.
There was protection on line, where computers were on, but projector was sharing same line with lights, so one of lights blow off and killed computer.
Seems thru VGA cable, cause other mac was not connected to a beamer and after this worked fine, and guy that was replacing motherboard said that it has a hole somewhere between thunderbolt and usb ports. At this time thanks for Gods I had a replacement, but from now on I would definitely check electricity so keep in mind too.
Cheers and good luck.