1 Prepare for safe work
Protect the floor and furniture, turn off hidden wiring in the drilling or cutting zone, and check the moisture and load capacity of the surface. Wear dust protection and work on a stable platform.
⚠ Warning: The coil spring of the strap winder can suddenly release energy. Wear safety glasses and do not disassemble the closed spring assembly without clear instructions.
2 Determine the pattern of the problem
Lower the roller shutter completely, open the box only from a stable ladder, and photograph the winding direction.
3 Check the most common cause
Secure the shaft, detach the old strap, and thread the new one along the same path through the guide without twisting.
4 Apply the appropriate solution
Pre-tension the winder according to the instructions, secure the strap, and test several slow cycles before closing the box.
? Tip: Photograph the initial state and change only one thing at a time so that you know which check really affected the result.
5 Test the result and set limits
Allow the material to dry or cure for the full period from the product specifications, then inspect the alignment, adhesion, and cracks under side light. Do not cover active moisture or structural problems with a finish coat.