Hard drive cables are a known issue in 2010/2011 MBPs. They were once acknowledged by Apple and replaced for free, but not anymore... Luckily they cost $10 on

Hard drive cables are a known issue in 2010/2011 MBPs. They were once acknowledged by Apple and replaced for free, but not anymore... Luckily they cost $10 on Amazon and can be replaced in 10 minutes with a small phillips screwdriver. I managed my school's computer repair room for IT and replaced at least a hundred of these cables while I was in school.