Diagnosis
The camera and parent unit have lost their secure wireless pair. The camera is powered on, but it's not communicating on the correct "handshake" with the monitor.
How to Fix It
You need to re-pair them. Start at the camera. 1) Find the small pinhole reset button on the back of the camera. 2) Using a paperclip, press and hold it for about 5 seconds until you hear a voice prompt from the camera saying "Ready to pair." 3) Now, on the parent unit, go into the settings menu (the gear icon). 4) Select "Add Camera" or "Pair Device" and follow the on-screen instructions. It will search for and find the camera in pairing mode. This process re-establishes the direct link.
If That Didn't Work
Power cycle everything. Unplug the camera from the wall and remove the parent unit from its charger. Wait 60 seconds. Plug the camera back in first and wait for its status light to settle. Then power on the parent unit. Finally, attempt the pairing process from step 3 above.
Heads Up
If you've recently changed your home Wi-Fi password or got a new router, you'll need to set up the camera's Wi-Fi connection again in the Motorola Connect app before the parent unit will be able to see it. The 'no signal' on the parent unit often means the camera itself is offline from the network.