A: Thank you for coming so quickly.
B: What seems to be the problem?
A: All the channels suddenly stopped working.
B: Did you make sure all the cables are plugged in?
A: Yes, I checked and double checked them.
B: There may be some kind of signal interference.
A: Is there any way you can test that?
B: Of course! Give me a moment, please.
A: Do you know what the problem is?
B: Not quite yet. So you can't change the channels?
A: No, not at all.
B: Well, you'll be able to once you change the remote batteries.