All right. Time circuits on.

2 seconds sound clip from the Back to the Future Part II movie soundboard.

You can hear this line at 01:01:52.926 in the Blu-ray version of the movie.

Quote context

[...]

- You're not gonna believe this.

- We gotta go back to 1955.

- I don't believe it.

- That's right, Doc. November 12, 1955.

- Unbelievable that Old Biff could've chosen that particular date.

- It could mean that that point in time inherently contains some sort of cosmic significance, almost as if it were the temporal junction point, for the entire space-time continuum. On the other hand, it could just be an amazing coincidence.

- Damn! Got to fix that thing.

- All right. Time circuits on.

- What do you mean, time circuits on? Doc, we're not going back now!

- Yep.

- Doc, what about Jennifer? What about Einstein? We can't just leave them here.

- Don't worry, Marty. Assuming we succeed in our mission, this alternate 1985 will be changed back into the real 1985, instantaneously transforming around Jennifer and Einie.

- Jennifer and Einie will be fine, and they will have absolutely no memory of this horrible place.

[...]