I left my Hitachi 640gb hard drive on all night and now when I power it on I hear clicking and beeping and skipping and my laptop won't recognize it. it must've overheated or something. I've had it for two years and it's worked flawlessly, and i've never dropped it once. But i'm really worried b/c I have over 500gb of important files on it and I don't want to pay upwards of 700$ for data recovery. Is there any thing I can do to fix it on my own, and any explanations of what it could be would be much appreciated. It it dying? Could it be faulty hardware? Has my power supply burned out? Insufficient power?