So I was moving some files from my 500gb external hard drive today and it froze mid process. I waited for about 10 minutes, put a fan on it, as it has been pretty warm lately, and came back to find it was still frozen. I ejected it with no success, which then closed my entire OS down, restarted, plugged in, powered on, and now it doesn't even show up anywhere. I took it all apart to make sure the connections were all good and even took alot of the casing off to make sure heat could escape better and still, to no avail, I can't access any of my almost 500gb worth of files. What do I do from here?