Ask HN: What do you do when you've lost motivation at work?

I'm woundering how do you approach this kind of feeling when you don't feel motivated at work.

I think that majority of people will solve it with finding a new job or maybe take a vacation. But, this is all about long term soltions. What I want to know, how to turn your motivation back right away, without changing a job or taking a vacation. Is it even possible?