error: from internet , 維修兵團 homeguidecorner the most likely it's the carbon brush. This sounds easy.... Where to buy such carbon brush? Here: dimension of brush: 33 x 13 x 5 mm hkd 50 a piece, two pieces costs hkd 100 ( asof Dec 2023) but not sure this shop will still be running 5 or 10 years later Taking the motor out is not so difficult. At least not the most difficult one when comparing the other steps. connector is 7 positions, but only have 6 connector blades The 2 mounting hex screws is 10mm. The motor refuses to come out and you have to lean the machine on it's back , and pry the motor out from the other end Welling (威靈） HXGN-1L 82 universal motor, (F type?) Supplier code: 400010580038 The last 2 digits refer to different type of box connectirs and no of blade pins in that connector 54-00310-02-08 Just a centimeter remaining from original brush: The carbon brush is within a holder, which has a spring, and a copper braid to connect to the carbon br...