I have a late 2011 13-inch MacBook Pro that gets a circle with a line through it on start up. The drive is a two-month old new SSD that shows no problems when tested in Disk Utility. I've put the drive on an external enclosure and I'm able to boot to it w/o any issues on the same laptop. I have a late 2012 13-inch MacBook Pro and I swapped out the hard drive cable to the 2011 laptop and I have same circle appear. When I took the 2011 hard drive cable to the 2012 MBP it booted normally. Should the hard drive cable from the 2012 MBP work normally on the 2011 MBP? I'm thinking its the hard drive cable on the 2011 that is causing the problem. What are are you thoughts? Thank you for looking.