The loud clicking you're hearing is indicative of a hard drive failure. The fact that SMART has reported this means that is definitely the case. A failing hard drive can cause a system not to POST (not always though) and the fact it was dropped is probably how it got damaged. If you want a second opinion, feel free to grab a diagnostic from the hard drive manufacturer and test it. To be honest though, I'm certain it will tell you the same thing.
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