The repairman said the motor damage due to water but the weird part is I deep clean the unit before send for repair and didnt see any trace of water.
I take out the parts most of it but didnt touch the motor, till end I still cannot see trace of water or moisture.
I wont buy dyson as u said its overprice but this unit bought when I was in States and during boxing day + cybermonday sale around $179 with 12 months installment 0% interest. Its quite a deal I think so I grab it. 
no burning smell at all. Spinning shafts you mean the motor? Dont think hear can penetrate the filter, only small dust or water can
Yeah, chances to repair it myself is high now since I found the parts online
Wow means the repairman quote me same as Dyson service center price hahahah damn
Yup, found the video, not that complicated.