Flaky Arduino Micro Board

I have an Arduino (genuine, not knockoff) Micro, which I have been using for two weeks in a development project. I noticed tonight that the 7805 regulator I was feeding it with got too hot to touch. Then the Micro board went dark, and the micro on it was too hot to touch.

I unplugged the board entirely from my circuit, and just powered it through the USB connector. In that mode, it powers up, the LED's light, but then in under a minute, it goes dark, again with a very hot microprocessor. Even after it is dark, the board stays warm, so there is some power flowing to it.

Has anybody had a similar experience with this board, or does anybody have an explanation for this?Thanks in advance for any insights.

John Doner

The ATmega chip should never get hot. I would consider it as broken after it got hot.

One logical approach would be to promptly (after connecting,) load a simple "blink" sketch with no external connections, and see whether it continues with the problem behaviour. If it does, it's cooked, if it settles down, there would be some problem with the sketch and/ or circuit you are using.