I have replaced my cable and my hard drive is now functioning normally again. Unfortunately, the sleeping LED is no longer functioning. I've removed the HD once again and realized the lever wasn't down on the ZIF connector. I pushed it down and put the bracket back into place. Unfortunately, the LED is still not working. I am assuming the connector is either not far enough inside, or the LED on my new cable is broken. I am however reluctant to open everything up again but I am afraid I will break something on the connector, eventually. Am I risking any missing functionality on my Mac by not fixing the sleeping LED? Will my Mac/HD still fall asleep, do Bluetooth devices still work?