When I'm assigned as ECO, the first thing I do in the press box is familiarize myself with the console. Then I'll set the clock to 5 seconds and start it to check if the auto horn/siren is on. If it is, then I start going through the console menu options until I disable the auto horn. If it's a Daktronics console, I can usually get all that done and the clock ready for game time with 15 minutes or so to spare. Some of the other consoles may take longer (and as mentioned some can't be turned off at all).