If you aren't using the on board LED, you need a resistor. You first post sounds like you plugged an LED into it, rather than using the on board. If that's what you did, that's why your LED died.
If you aren't using the on board LED, you need a resistor. You first post sounds like you plugged an LED into it, rather than using the on board. If that's what you did, that's why your LED died.