53rd floor, 60611 zip. Bought brand new extender due to constant dropped calls on all 3 iPhones (1-2 bars at home, 4-5 outside) and set it up according to directions (connected to router, connected to power supply and plugged in, located right next to window). The power and WAN lights are blue. The system light is blinking red and the GPS is solid red. I waited over an hour, set it up again and again, tried GPS extension. Same problem. Our internet is fast and has always worked well. We have RCN cable/internet/landline bundle. Arris modem and Linksys E2500 router. I'm wondering whether the issue is being on a high floor.