It took me a while to figure that one out. So basically remember the rooms that you could see when the lights were on. You kinda need to try and navigate to those rooms by clicking on them, not only the arrows. I think they are more of a direction of looking. So when the lights were on and you clicked on the rooms it was pitch black an you couldn't enter them, you need to click on them when the lights go off. I think it was of the rooms, near the writing on the wall, I could be wrong.
If you can't use the phone, try reloading the game. Hope this helps