So I had this back tonight.
Wheels swapped over, lesson learnt there!
But, 'it doesn't work well on carpets'... I gave it a go, and the brushroll wouldn't work, and the led's flashed at me in unison... Popped the hood off and the motor to cogs belt had snapped.
Immediatly remembering my attempt to dismantle them, and that I've probably broken the assembly, I swapped the good part off my x4. Job done, it works very well again!
Will splazz some grease on the end bearing tomorrow!
My x4 now hangs in the balance of parts costs vs spares worth... It needs:
And its not too mint either. I'll ignore that for now and see what comes up!
The customer is (or will be when she collects it) happy, which is the main thing!