Help with my trusty Dyson DC01?

When using my dyson, I realised it wasn't working properly. It made a 'popping' noise and there was a terrible smell and some smoke! A few days later I decided to have a look at it. The brushes weren't moving so I opened it, saw the belt was broken, cleaned it out and replaced the belt. However, when I switched it on the terrible smell and smoke reappeared....help!
I am female, so help in simple terms would be much appreciated. Also no comments about a female trying to fix a hoover! :)