Odd "tink" noise coming from laptop?

As of late, my laptop has been making the same sound it makes when you do a hard reset on it, which I can only describe as being similar to that of flipping a small, metal switch; kind of a subtle little “tchink” sound. It does this very occasionally, but it’s still enough to drive me insane. Any suggestions as to what this could be?

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It could be the cpu fan turning on, that would be my only guess.

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Thanks, Cam. That's a really good suggestion. Recently though, its hard drive went kaput, so I guess that's one less problem to worry about :P

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