Give thanks for robust hardware

Trying out my Pixelblaze for the first time today. I have one of those breadboard power supply things, takes 7-12V in, and depending on jumpers delivers 3.3V or 5V to the output pins. Used it a bunch of times for many things. So I hook up the Pixelblaze to the power & ground rails, connect an led strip to the rails plus the data pin, a 12V power supply to the breadboard power, and hit the on button. I spent a good 3-5 minutes trying to connect unsuccessfully to the wifi. When I go to look at the board, I notice a LOT of heat coming off the metal shield on top.
I very quickly power it off, disconnect all the wires, and when I check the power, what should be the 5V rail is at ~11V. If I move the jumper to 3.3V it puts out 3.3, but at the 5V setting it’s putting out nearly the full 12V. I was convinced I had probably just destroyed my new board. But lo & behold, hooked it up to the USB port on my laptop, it fired up, I connect, and away I go.


Thanks @UnstoppableDrew!
I put in high voltage protection (up to 18v) and reverse polarity protection for cases like this. It’s good to hear those kicked in and saved the board!

Bummer about the power supply!