"Why won't MacBook turn on after changing SATA cable?"に関する回答I have a very same issue: The old HDD cable failed on my MacBook early 2011, so I purchased a new one. Connected it and MacBook would not turn on. Removed it - it works fine and turns on. Add it again - no life at all. So I opened another Macbook early 2011 which is fully working, disconnected the original HDD cable and connected this one (exactly the same models) - it would not start up at all - no life, nothing happens. Remove the new cable - starts as usual, no issues. So I have asked the seller to replace and I will update you when that happens. I suspect the cable is faulty.