What is wrong with my Aquaviva Candy 1200? :(?

At first the machine would wash, drain & spin as normal. Then it would wash and drain BUT not spin. The drum doesn't feel as though there is a problem when you manually turn it. I left it for a few days in case any dampness had got into the motor. When I turned it back on the control dial clicked through every programme one by one until it had done x2 360 degree turn on the dial!!?? When I took the lid off the machine I noticed very fine black dust and someone told me this might mean the 'brushes' may need changed... Does this sound correct or do you think there is another underlying problem??