Hello from a newbie member. I have an old MBP 3.1, A1229, core 2 duo, 2.4ghz, mid/late 2007. Currently running Mavericks OS X 10.9.5 . Runs fine on Mavericks but want advice if I should upgrade to El Capitan? I added memory years ago so that's not an issue. As I understand it, El Capitan would be the highest OS X I can upgrade to. In excellent shape despite just getting a new battery, and the screen is dimming. My next question will be related to the dim screen...replace the ccfl lamp or buy a whole new top on ebay?