A1 is a pure power meter rather than an intelligent cycling trainer, so it is necessary to select the ‘power meter’ when connecting, but it cannot be connected if ‘the intelligent cycling trainer’ is selected. If the ‘power meter’ is still not connected, confirm whether the Bluetooth mode of the device is on or not. If the connection is indeed not connected, the speed sensor needs to be replaced. If you need to replace the speed sensor, please contact service2@thinkrider.com  and we will provide you with a new speed sensor. You can learn how to do it in the video below.
A1 speed sensor to replace video: https://youtu.be/3F0FcukS18Y