You had me worried me for a bit, Dyson and repair aren't usually used in the same sentence. I can't help with your question. They don't make it obvious do they.
Oh they can be. $150 per incident to repair and THEY'RE the only ones that can repair it, regardless if it's in warranty or out.
I found a great site for doing it yourself, took some digging last night, but I managed.
Replacing the cord is easy and they won't know shit if I do it. http://www.sparesaver.com/help-and-support/dyson-section/dyson-technical-advice-450/
pass it on if you know anyone that owns one.
Oh and wait times are 4-6 weeks to get your vacuum back, no thanks. lol