How can I change the signal?

Hint 1 of 8:

Did you notice the breaker panel?

Hint 2 of 8:

Did you try opening it?

Hint 3 of 8:

Some help might be useful.

Hint 4 of 8:

You still have that dagger.

Hint 5 of 8:

Did you examine the crack?

Hint 6 of 8:

And did you use the weighing machine?

Hint 7 of 8:

Do you recall the trick with the credit card for opening doors?

Hint 8 of 8:

Use the card from the weighing machine on the crack and the panel will open.