Hi @Samo61,
Welcome to the Dyson Community!
Just to clarify, did you replace the complete Main body assembly (containing the motor), or have you sourced and replaced just the motor itself?
If you’ve replaced the motor individually, it’s possible it hasn’t been correctly reconnected or reassembled, or a remaining component could have sustained damage. But if this repair wasn’t completed by a Dyson engineer, it would be very difficult for us to pinpoint exactly what may be wrong in this particular instance.
We can only really suggest checking that all components are correctly connected and reassembled.
You could also contact Dyson Customer Care directly for replacement parts or a repair by visiting Dyson.com and clicking Support to get in touch with the right Dyson Customer Care team for your region.