What could be wrong with my Miele Vacuum cleaner?

I have a Miele S290. After changing bags and filters it made a whining noise and then came to a stop. Could not get it to start again. Changed fuse. No luck. Took apart, cleaned it out and tried again. Nothing.
Plugged it in again today and it briefly started and sounded like normal but cut out after just a couple of seconds. I originally thought the motor had gone, but after it temporarily started today I have changed my mind. Could there be a loose wire in the moulded plug?
Should I cut it off and replace with a standard plug?
I bought this cleaner because I thought Miele products were long lasting. I've had this about 3 years and looked after it well.
Please can somebody help me with some ideas as it is too expensive to call out a repair man.
My husband is useless at DIY and I am no expert.
Any advice would be kindly accepted.
Thank you
Mrs DG