I know almost nothing on MAC OS. I was following thru this video, I have a brand new SSD inside this mac, as the last one could be dead. I press the Option button as it boots up w/ that music sound I then see the symbol of Install Sierra OS. But I don't see the icon of MAC HD, so I thought it's a bad sign, it looks like the MAC Book pro can't see the drive. Does that mean the controller fails? As even w/ a blank SSD, the laptop should still shows the MAC HD icon, should it not? what can I do?