This question already has an answer here:
Just got an SD card: SanDisk Ultra 32GB microSDHC UHS-I Card with Adapter, Grey/Red, Standard Packaging (SDSQUNC-032G-GN6MA) (http://www.amazon.com/gp/product/B010Q57T02) Formatted it with SDFormatter and put NOOBs files one it.
Pi doesn't boot - solid red and solid green upon bootup.
I tried putting the Raspbian image on the card and the same problem.
Mac Utility says that the disk is fine. What else can I try before I go get another SD Card?