A broken torsion spring gets replaced, not patched - there's no safe partial fix for a spring that's already let go, and we size the new one to the door's actual weight rather than whatever was on it before. Cables, drums, and worn rollers get checked at the same time, since a cable that's frayed enough to jump usually means the spring was already past due.
For doors that are off-track but the spring is intact, realigning the track and replacing bent rollers is often enough, and it's a cheaper repair - we'll tell you when that's the case rather than selling a bigger job. If the opener itself is the failure, we diagnose the circuit board, gears, or sensor alignment before swapping parts.
One limit worth being honest about: if the door is original to a house built decades ago and the track or hardware is no longer made, we'll say so rather than hunting for a part that doesn't exist anymore. At that point patch repair stops making sense and replacement is the better money.