Unfortunately, this behavior is usually and indication of an internal power supply problem with the Express.
Try the following as a "last chance" attempt to see if a Factory Default Reset will help:
Power off the Express for a few minutes
Hold in the reset button first with a pen, and continue to hold it in for an additional 9-10 seconds while you simultaneously plug the Express back in to power
Wait a full minute for the Express to restart
If the Express is operating correctly, the amber light will stay solid for 25-30 seconds or so and then begin to slowly blink amber
If you try the Factory Default Reset a few times with no improvement, the Express will need to be replaced.