Brownout on Due

I have an Arduino Due that will brown out about 30 seconds after power over USB or VIn. The builtin LEDs (ON and L) will slowly get simmer until they turn off or sometimes one of them will start pulsing (there is no LED flash in my code). A small chip that I think is a voltage regulator gets very hot while this happens (picture attached of that chip, has 3 thin legs and 1 thick one). I think I have narrowed the source of the problem to a few possibilities. 1: I applied 12 to a 5v pin, or I had a reverse voltage to the 5v pin. I would like to know what this chip is and if I can fix it. I have an official Arduino Due.

First the Due is a 3.3V board... when you say 5V pin it makes me nervous... but I'm guessing you mean the power pin... i hope.

DUE

That part is NCP1117ST33T3G -3V3 on the Due schematic... it is a linear voltage regulator.

Reversing voltage will kill that let's hope that's all the damage done to it as the main IC pins will not tolerate 12V either.

The Due is designed to work under those conditions. Is there something you are not telling us ?
Is there ANYTHING WHATSOEVER connected to it (other than power) ?

Reverse voltage to 5v pin would kill that regulator it bypasses the reverse protection.

Answer is yes the regulator can be changed. It’s SMD so removal can be tricky without the proper tools so nothing else get damaged. Those header pins will not take much heat without melting. Try a lot of flux, put some klaxon tape around those headers. And wick away the solder. Or if you have a hot air set up. Heat it up and remove. Then replace with a known good part.

Your symptoms sound like a regulator problem. There may be more damage that hasn’t shown yet with reverse polarity.

Ok thanks everyone for the quick replies. By the 5v pin, I meant the power pin, that’s the only one that accidentally received 12 volts. Everything else should be fine. I should be able to fix it with the info you’ve given me