If you have a Chuxaway SC or SCX and need to replace the cord, please remove the 4 screws on the lid of the motor unit to expose the motor. The new cord should be threaded through the tiny hole on the motor spindle. The hole is behind (under) the metal dome. Ensure that the cord is then securely tied back on itself. Wind the cord a few times anticlockwise around the spindle. The cord should then hang from the spindle on the left side. Then it is essential to route as shown such that it passes behind the metal lever of the internal micro-switch as shown here else the door will not lower.
Please click here to see a video illustrating the cord routing and impact of not routing correctly.