The issue are having is most likely hardware related. Though it might not be the HDX having the issue. It could be your mic or camera. It could be one of the cables have gone bad. What you would need to do is find out what part is having this issue. So first I would disconnect everything but power and monitor one. If the issue is still having it is most likely something with your HDX. If you don't have the problem then maybe the camera or mic. So if it does boot up I would turn off the HDX and connect the camera. If it boots up then turn off the unit and connect the mic. If the unit boots up maybe you just needed to have the cables reseated. If not then if could be that device and you should contact support with your issue.
