Safety: Garage doors are heavy and spring/cable systems can be under significant tension. Do not loosen or disassemble high-tension hardware unless you are qualified to do so.
High-Load Components
Springs, cables, drums, brackets, and rollers should be checked for visible damage, wear, looseness, or abnormal movement.
Opener Safety
Photo-eye sensors, reversal behavior, controls, and door travel should function without bypassed safety devices.
Door Movement
A door that binds, shakes, drifts, or moves unevenly deserves attention even if it still completes a cycle.