He says he's found the main controls to the power beam that's holding the ship here.
6 seconds sound clip from the Star Wars: Episode IV - A New Hope (1977) movie soundboard.
You can hear this line at 01:09:23 in the Blu-ray version of the movie.
Quote context
[...]
- Take over. We've got a bad transmitter. I'll see what I can do.
- Bring them on! I'd prefer a straight fight to all this sneakin' around.
- He says he's found the main controls to the power beam that's holding the ship here.
- He'll try to make the precise location appear on the monitor.
- The tractor beam is coupled to the main reactor in seven locations.
- A power loss at one of the terminals will allow the ship to leave.
- I don't think you boys can help. I must go alone.
[...]