no signal on remote

Well to me that sounds like it can be two things. I would check the Sensor Bar to to make sure it is okay. Obviously check to see that it is plugged in, that the cable is still intact (in case you have a puppy or a mean little brother), and that it is facing the Wii remote. If you are sure that the Sensor Bar is okay then jump to the next step. If you are not sure if they bar is good, bring it to a electronics store or preferably a Gamestop or similar gaming specialty store and ask them to test the bar. (They should not charge you for something so menial) If it is bad then simply purchase a new one and have fun playing tennis. (It's your favorite Wii sports game, so don't kid yourself!)

If you have come to this step then you probably need to re-sync your Wii Remote. To do this lift the card reader cover to reveal a red button. Additionally underneath the cover for the battery on the remote there is another red button. First press and hold the red button for 5 seconds on the Wii and then press the red button on one of your remotes to sync them together. Once synced it should start working normally and if not then your remote is probably bad. :(