There are several ways to tell if there is a problem with your garage door. One way is to check the sensors. If the sensors are not aligned, it could be a sign that there is a problem. You can also listen to strange noises when the garage door is opening or closing. If you notice that your garage door is taking longer than usual to open or close, it could be a sign that there is something wrong. Finally, you can check the balance of your garage door by lifting it up manually. If it feels too heavy to lift, there may be a problem.