Today I was wiring end-stop switches using this video on my Arduino Mega 2560 R3 an Ramps 1.6 making sure the wire were exactly the same as the video.

Well I blew the AMS1117-05 in a heartbeat so today I replace the AMS1117-05 with a DC-DC Step Down Buck Converter 1.5V 3V 5V 9V 12V 3A Adjustable Module this was set to the 5V jumper.
DC-DC down converter.jpg

My question is why did this switch made by BigTree-Tech.com for maker bot kill the AMS1117-05, tested the switch it operated correctly.

I must be right at the max current limit for the regulator because when I power it on with the new regulator is now works correctly.