On a door this age, the spring is the big one - it's the part rated for a cycle count, and Maple Valley's housing stock is old enough now that a lot of original springs are near or past that limit. Rollers are next: the stock plastic rollers that shipped with a 2000-built door are brittle by now, and a cracked roller binding in the track puts uneven strain on the opener. Cables fray at the same rate as the spring wears, since they share the load. We also see original openers with worn drive gears - the motor still runs, but it's grinding instead of lifting, which is usually the first sign the gear is stripped.