https://forum.arduino.cc/t/connecting-pin-5v-intollerant-to-source-pulled-up-by-30kohm-to-5v-bad/271223
Connecting pin (5v intollerant) to source pulled up (by 30kOhm) to 5v. Bad? - Due - Arduino Forum
Nov 21, 2014 - I've recently broken a pin on my DUE (it's stuck at 3v now). I'm assuming it is because it had been connected to a node at 5v (pulled high by 30kOhm). I...