20 - 30 minuten
After getting the Folder with a Question mark when booting, I decided that the HDD had failed. Ordered a new one, installed it and still had the Question mark. I decided to gamble and ordered the HD cable, even though there are worst case scenario stories of mother board failures causing similar symptoms.
Everything went well with the cable install except, the mid cable anchor screws were a little more difficult to line up correctly because of the stiffness of the cable. Reassembled, booted (using a recovery USB jump drive I had created previously) and got the Apple. Total time, about 30 minutes.
Epilogue: How can a just over a year old NOS MacBook Pro's HD cable go bad? I dunno, but it did. Given the symptoms, I would recommend replacing the cable first, it's cheaper. It was still a win situation for me (even with the un-needed extra expense of a new HDD) in that, the replacement drive was larger (1TB) and faster (7200 rpm with a 32MB buffer). I still have the working 750GB OEM HDD waiting in the wings, in case I need it in the future.