I bought a Seagate Momentus XT for my Macbook Pro. I installed it as per the detailed instructions, but it does not appear to be starting up. The Seagate has a spot for a power cable, which the original drive did not have. The Macbook does not have a power cable, so I'm not sure what to do. I bought this drive specifically because several people have said it worked fine in their Macbook, so perhaps I have a bad drive, but I'm not sure.

I put the original drive back in to confirm I did everything correctly and it started up fine.