I still think the pin used for calibration is damaged. And I think if you reassign another pin for calibration and upload it, it will work again. You just need to work around the I/O pin not receiving the signal to stop calibration mode.
What Jerry was talking about with shorting against the heatsink, is what happened to mine and his solution was go around to another I/O pin. And it worked perfectly. I just have to remember that code change when I compile another version.
