The most common surprise on a late-1980s door in this area isn't the spring itself, it's what's attached to it. Drums, cables, and bottom brackets from the original install are often original too, and if one of those is worn, a spring-only repair won't hold. We check the full assembly before quoting a fix, and if the drum shows groove wear or the cable's frayed, that's an added repair, not a separate visit, assuming we're already on the ladder. On the opener side, a failing capacitor can look exactly like a dead motor, and replacing the whole opener when the capacitor was the real issue is money wasted. One honest limit: if your opener is a discontinued model with no parts support, we'll say so rather than quote a part we can't actually source.