I'm not sure, but I think the booster may be on the same circuit as the main (12 volt) TV, which appears to be the first fuse in the distribution center panel (near the floor in the kitchen).
But...it may be easier to simply check all the fuses in both the distribution center and the battery control center (kitchen side of the stairwell).
The 12 volt testers - a probe with a light on it with a wire to an alligator clip - work well to test fuses. Attach the alligator clip to a good ground, then use the probe on each fuse. If you're not sure which side of the fuse is hot, simply test both sides. One side of the blown fuse will turn the light on, the other won't. Both sides will turn the light on if the fuse is good.
PS - It's also possible that the booster has it's own inline fuse...