Repairing a Roller Shade

• A window shade works by tightening or loosening a spring that is connected to a gear or ratchet. When the shade is extended and not moving, the gear is held in place by a pair of pawls that prevent the wound spring from uncoiling. A sharp tug to the bottom of the shade forces the pawls out of the ratchet and allows the spring to unwind. An unwound spring causes the shade to roll up. The shade itself is attached to the roller by staples.
  
  If you pull on the shade and it rolls up with excessive speed or force, then the spring is under too much tension because the shade is wound too tightly on the roller This problem can be solved by taking the shade down from the window, unwinding it a couple of inches and putting it back in place. Conversely, if the shade does not go up or goes up slowly, there is not enough tension on the spring. Rewinding the shade around the roller should set things right.
  
  Mounting brackets are often to blame for shade problems. If the brackets hold the roller too tightly (the brackets are too close together), the shade may wrinkle and bind as it rolls up. This can can cause damage to the spring. Move the brackets farther apart. If the shade will not catch when it is snapped, the brackets may be misaligned, causing the pawls inside the roller not to engage the ratchet. If the brackets are not misaligned, then the problem is with the pawl/ratchet/spring assembly and replacement is the only option. If the shade will not stay up, chances are good that the spring is damaged. Again, replacing the roller is the only option.
  If replacing the roller is called for, it is possible to buy just the roller, preserving the shade material. The ratchet/spring assembly extends only partially through the roller, allowing one end to be cut to fit your window.