DIAGNOSIS The robot lost its Wi-Fi connection, usually after a router change or password update.
FIX Press and hold the Wi-Fi button on the robot (next to the CLEAN button) for 10 seconds until it beeps and the light pulses blue. Delete the robot from the iRobot app. Then re-add it as a new product, following the in-app setup exactly.
IF THAT DIDN'T WORK Ensure your phone is on the 2.4 GHz band of your Wi-Fi. The 694 does not connect to 5 GHz networks. Temporarily disable 5 GHz on your router or move the robot/dock closer to the router during setup.
HEADS UP The robot and your phone must be on the same Wi-Fi network for setup. Don't use a guest network or a network with AP isolation enabled.