A door that won't open past a few inches and then stops, with a loud bang beforehand, is almost always a broken spring - common on the original torsion setups still in a lot of Waterflow's 1986-vintage houses. A door that reverses halfway down, every time, points to a misaligned or dirty photo-eye sensor, which is a five-minute fix more often than not.
A door that opens unevenly, one side higher than the other, usually means a cable has slipped off its drum or a roller has failed on one track. Grinding or screeching on the way up, especially in colder months, is often just hardware that hasn't been lubricated in years, aggravated by the severe cold this area sees - but it can also be a sign a bearing is failing and about to go.
If the opener runs but the door doesn't move, the issue is usually the drive gear inside the opener unit, not the door itself. Knowing which of these you're looking at before the truck arrives helps us bring the right part on the 16-mile drive instead of a second trip.