Garage Door sensor problems

Thanks to several YouTube videos, here's how I fixed my garage door problems.  I AM NOT A GARAGE DOOR MECHANIC.  My garage door wouldn't close when I would push the button.  The light would just blink.  My sensors were aligned properly, but I noticed the light on the sensors was out.  Any tv remote will work, I pointed the tv remote at the green lighted sensor and pushed any button, and the light started flashing on the sensor.  I knew it had to be the other sensor was bad.  So I changed it out and it fixed my problem.