Check the power cord. If it's not securely plugged in to an electrical socket (or not plugged in at all), the message does not start until you securely plug it in.
Locate the power switch on the back of the chair. It's on the lower-left side of the back of the chair. If it's set to "Off," switch it to "On."
Unplug the chair and plug it into another electrical socket. The one you have it currently plugged into may not be providing power to the chair.
Check the controller for flashing lights if the massage suddenly stops. The massage heads my have been forcibly locked, at which point they stop for safety. Find the "Start/Reset" button on the remote and press it.
Watch the message heads when transitioning from a kneading massage to a rolling massage. When the heads are at their narrowest position, the chair has completed the transition.
Adjust your position on the chair if the massage heads do not reach your shoulders.