Hi Jay,
looks like you may have uplaoded an arduino sketch at some point and that is preventing new sketches to be uploaded.
please try putting the board in bootloader mode by quickly doubletapping the button on the board. if you do that right the LED should start pulsing gently.
in that condition check again the serial port to which you need to load (it should change with respect to the one in application mode) and try uploading the sketch again.
i don't think there's any hw problem as you would not even see an USB uart otherwise. also if you connect the micro hdmi connector you should see the arduino logo.
let me know if you still have issues.
thanks,
Dario