When upright vacuum not on but when tilted to vacuum it runs if the brush is activated. If you push the button to stop the brush, vacuum motor stops. The main power button works.

Sorry mate the dc17 isn't a UK spec machine so I cannot help . Any dyson stores near to you ?

Well, my friend, I don't use DC17 vacuum but you can do one thing is that I would suggest flipping the vacuum over and removing the big plastic screws. Clean the beater bar (the cylinder with bristles) and try to see if it fixes the issue. Try fixing it at your own risk, my friend. I use Dyson Ball Animal Vacuum that comes is corded with 35ft cord, its power is 270 AW, its filters are washable, it's bagless and contains dirt container.