Probably one of the fuses in a "back stab"
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The fact that it was wired recently, not by you, suggests to me a builder.  Builders like to use the "back stab" connections on switches and receptacles, because it takes 1 second to jab a wire in, instead of 30 seconds to attach a side screw.  

Unfortunately, the backstab connections have "fuses" in them.  Well, not literally.  What they have is 50 years of product evolution with UL pressuring the industry very hard to design so they fail "hard open" (like a fuse) *rather than the alternative -- destructive arcing that will start fires*. 

So most likely, the power reaches this dimmer via a chain of other receptacles or dimmers, and one of those has "blown its fuse".  

Your best bet is to go to each receptacle and switch in the circuit and convert any backstabs to side screws.  Be sure to read our Q&A here called "First time changing switches and receptacles, anything I should know?" And also read up on doing side screws correctly.   

If you have an instance where you need to put 2 wires on a screw, they make "spec grade" receptacles and switches which have a "screw and clamp" back-wire system that does that.  These are $3 instead of 75 cents.