Check the track. If your garage door isn't opening and closing or isn't operating smoothly, first check the track from the door all the way up. If the edges of the track have been bent or are crooked, simply straightening them out with a few gentle taps of a hammer should correct the problem. Debris can also get stuck in the track and prevent the door's smooth operation. Remove any leaves, garbage or caked-in dirt from the track with your fingers or a screwdriver if tightly packed.
Check that the wheels move freely and aren't stuck because of debris and dirt. Clean the wheel area by removing debris; wipe the area with a sponge and cleaning solution. You can use some lubricant if the wheel is sticky.
Check your remote's batteries; sometimes the obvious solution is overlooked. If your garage door isn't opening and closing and you have an electric opener installed, check the batteries in your remote. You may need to replace them.
Check the power supply. Most electric garage door openers operate on electricity from a cord plugged into an outlet. First check that the cord is secure in the outlet and then check your circuit breaker box to ensure that no breakers have been tripped. If other electric devices in the garage--such as a light bulb--are functioning or other outlets are live, try plugging something else into the outlet to make sure it is receiving power also. Check the cord for fraying, chewing or other damage, which can cause power failure.
Check that the infrared sensors are working. If the infrared sensors are malfunctioning, the sensor lights may be blinking or inactive. Possible causes include a blocked path between the sensors, dirty sensor eyes, loose wires or just bad sensors. In this case, the remote will not work to close the garage door, and you will only be able to operate it using the wall button or console. Make sure the eyes on the sensors are clean and directed at each other. Unplugging the opener and plugging it back in may reset the sensors. If nothing works, you may have to replace the sensors.
Check for shorts in the wiring or transmitter (remote). If your garage door is opening and closing by itself, you need to isolate where the short is. Remove the batteries in the remote and operate the garage door manually using the wall button. If the problem persists or is intermittent, it could be a short in the button wiring or wall. If removing the batteries corrects the problem, the issue was with the transmitter. You will need to purchase a replacement from your garage door manufacturer's website or service center.