no power changes fuse still no power-cleaned filter-still no power-checked switch seems wiring connnected ok
initially switch appliance off then would not restart
(user believed had pulled wire to hard so stopped appliance to check plug not been pulled out of socket adjacent room
could be a break in the cable in which most cases are not visible have had this happen on mine you need to get the cable tested(can do it yourself if you have a voltage meter) also could be the brushes on the motor or the motor itself if there was no smell when it stopped working it is likely to be the cable you can buy used tested cables on ebay quite cheaply also can but tested motors on ebay for £16-50 including p & P make sure wires are pushed on switch fully dysons are quite easy to repair yourself if you are DIY minded email me direct if you want on redmikekite@yahoo.co.uk
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix vacuum cleaners.