Dyson DC07 won't pick up in carpet mode?

My Dyson DC07 was make a LOUD noise when using it. It also would not pick up. We replaced the first belt thinking it was the one you could see. Same noise. Replaced the inner belt and the noise is no longer there, however, it will not pick up while in carpet mode. Looks like the brush is not spinning. It just pushes the dog hair forward. No noise anymore though.