nice screen! I know we have heard of people having problems when powering thru the 5v and 3.3v pins… I have always said the 3v3 pin is designed as a supply not a point of intake… but people call me a lier and dumb all the time…
I cant think of any reason the power would do this other that a voltage - current issue… you already checked the while serial thing so as long as the processor is working and not hung in a setup loop… it must be power… if you have a variable power supply try applying 5v on the pin and letting the internal regulator produce the 3v3