So I know there have been discussions on this, but, I didn't find any searching, and they don't describe my particular issue anyways. So I was at school, and normally, I carry my Macbook with me in my backpack, but today, I had to put my backpack in my locker. So I'm holding my Macbook and a book in my hand, and couldn't get my backpack in, so what do I do? Without thinking, I drop it. Boom. It hit me the second I dropped it, I was almost in tears. I had just dropped my macbook forcefully onto hard floors from about 3 feet up. When I took it to class, it appeared to be fine. I noticed the lid casing was a little off-centre, but that doesn't worry me too much. When I opened it, the screen was a weird blue tint, and a little loading bar was showing on the bottom, when it reached the end, my screen went back to normal and everything seemed fine. It was still able to open all the apps on my computer without unusable laggage (though I can't be sure if it was any worse than normal or not), though sometimes when I'm typing after I start it up, it will give me a beach ball for like two seconds before showing the rest of the text. Not a huge issue, but obviously something annoying. It also did that blue-tint thing again a while later while awakening it. I'm afraid I may have damaged it on the inside (and I am a High School student who barely had the money to buy it in the first place, let alone fix it) in some way or another, in a way that is not plainly obvious by looking at it. The screen is fine, too. My question is, is there some sort of diagnostic mode for the computer to run through it's hardware and detect any problems? Any help as soon as possible is appreciated...Thanks, guys... P.S. It takes a little longer to physically turn on, now, too..Hangs at the initial blue screen a moment before dinging and going to the Apple.