Your motor brushes will probably have had a retaining mechanism on them. On the side of each motor brush is a small brass tag which you need to push with a small mains tester screwdriver. Push the tag towards the direction of the motor comm whilst the brush is located in the motor. you should hear a small click. This should bring the carbon into contact with the comm. Do this for the other brush and replace the lid and try the machine. If you have done this properly and the motor still does not turn, the old brushes may have caused a spark to go back to the module of the w/m and blown the module. this is very unlikely on this motor/ w/m combination however!
The 9577 is quite an old machine so you can't rule out total motor failure altogether. The motor insulation may have broken down and the motor may have lost magnetism. A new motor is the remedy in this case!
John
April 2006