Anything can go wrong with garage door openers since they're powered by electricity. A simple power outage could cause trouble. Wire damage would stop the opener from working. Problems with the socket might even burn the motor. When electricity is involved, things are easier but trouble is also nearby. Though, opener issues aren't always centered on wires and motors. They might be related with the chain or even its emergency release cord. Every little part of the operating system might need repair and cause troubles but fortunately for us most problems have rather easy solutions.
The problem with opener problems is that they might compromise your safety. The simplest wire issue will make the sensors unable to work right. If the photo eyes don't see you when you are passing under the overhead door, you might get hurt. Whether sensors give trouble often or not, they still need to be maintained often. The door won't be absolutely safe if the opener parts aren't tightened well. If their fasteners are loose, they'll vibrate and become safety hazards. It's important to verify that the opener unit is well-fastened against the angle iron.
Most problems related to electric operators appear as symptoms with the way the door moves. Since the force of the door and the point where it will close and open are all set by the opener unit, you might find that the door won't reach its full opening position or won't reach the floor. In these cases, you'll have to use the UP or DOWN button or switch at the opener to set the door right. Another common problem is when the door reverses before or after touching the floor. Since its operation is done through the reverse system, this is the cause of trouble. If the sensors are aligned, press with persistence the wall button to override the reverse mechanism and close the door but there will be need for garage door opener repair.