Stuck Tachometer Needle

The needle on my tachometer is stuck at 1800 RPM. The needle does not move when the engine is running. What are the chances that the tach can't be repaired and needs to be replaced?

Thank you. I am trying to decide whether I should order the replacement now as the fastest path to a complete fix while the boat is on the trailer. I won't be able to start the engine and test the tach until the boat is launched. Once the boat is launched, my ability to fiddle with it will be limited. I guess I am asking if there could be any possible explanation for the stuck needle than a bad tach. I can't imagine that a a bad wire or connection would cause that.

I decided to pull the tach tonight. It turns out that a wire was disconnected. After reconnecting it, the needle moved when I cranked the engine. It was not so much stuck as unmoved. The tach does not settle to zero when the engine is off. I'll see what happens when I run the boat in a few weeks and decide what to do from there.