Hi, I have a 2012 27 inch iMac with a fusion drive. I always keep it stationary when in use. But yesterday a family member bumped it whilst it was on. The display section of the iMac pivoted along its hinge to the maximum it can rotate forward and then shook a bit from the impact. How do I go about testing that hard drive for damage? I know I can use the disk diagnostics tool to do a quick check but that doesn't test if there was any surface damage to the hard disk's surface. What would you recommend? Thanks for the help!