- Manual drive components
- Direct push-up operation, a hand-chain hoist or another manual drive has its own chain, wheel, reduction and keeper parts. Wear and accessibility determine the tasks included.
- Powered operator repairs
- Brake, motor, reduction, sprocket, roller chain, limits and internal controls are assessed separately. The operator's identity and compatibility with the balanced door guide part selection.
- Protective device scope
- Photoelectric sensors, sensing edges, light arrays and vehicle-detection accessories serve defined roles. Quantity, mounting, wiring condition and operator requirements determine repair and test work.