A door installed around 1980 has had roughly four and a half decades of daily cycles, and extension springs from that era typically fail from metal fatigue rather than sudden shock - they stretch, lose tension unevenly, and eventually snap a coil. Because Fallbrook sits in a mild temperate band without the hard freeze-thaw cycles that crack hardware in colder climates, the springs and cables here usually fail from age and cycle count, not weather damage. That's a slower, more predictable failure than what we see in harsher climates, which is one reason a lot of these doors are still running on original springs well past when they should have been swapped. The other common issue on houses this age is a worn torsion tube bearing or a track that's shifted slightly out of plumb after years of settling - neither dramatic, both eventually disabling. We don't see much rust-through on cables here the way you would in a coastal fog belt; when a cable fails locally it's almost always fraying from an out-of-round drum, not corrosion.