The brushes will not rotate

Sounds like they are probably jammed. Look at them and look near the edges for hair and other objects that are entangled within the brushes. If you see anything, a seam ripper or letter opener is the best and easiest option but if you dont have any, scissors will work as well. If you see anything, use one of the tools above to remove it. Once its all removed test it. If it still isnt working theres probably a bigger issue and you can contact Roomba and see if they can fix it for you.

Hope this helps and good luck fixing!