Here’s my toasted board. Is that the regulator?
Don’t know what caused this. I provided 5.0 V through the visible wire.
OK, that’s a voltage regulator and those will burn out if you’ve connected 5 volts to the board but connected it backwards. (positive connected to ground and ground connected to positive.)
It’s very likely every chip on the board got fried, but there’s a small chance it’s just the voltage regulator that got fried.
What you can do to test is connect positive 3.3 volts to the “3V3” pin and negative to the “GND” pin on the side of the board and see if the board comes to life and is programmable. If that doesn’t work, you will need to replace the board.
