Hi,
Don't waste your money buying 'service discs' all of the information you need is totally free. go to www.dyson-online.com and click on 'Help & Support' then select either 'Technical Advice or 'Hints & Tips'. All the information and parts you need will be there.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix vacuum cleaners.