My Problem

Replaced original HD but did not install it in the rails. This caused the HD to rub against the data cable and short it out.

My Fix

Ordered new cable, followed the iFixit replacement directions, and the installation went smoothly and successfully!

My Advice

The mounting screws were VERY SMALL for my FAT FINGERS. Be very careful when picking up and replacing those 4 screws. They can get lost on the main board very easily.