Author Topic: Dyson V8 (SV10) Brush Bars Won't Spin (Read 3028 times)

DreWRX · « **on:** June 20, 2021, 05:30:17 pm »

Hi there, have a problem with my V8. Was gifted a V8 due to both brush heads not spinning. Unit is in immaculate condition and main motor spins fine at both speeds. Replaced battery with fresh Dyson brand. Completely tore down unit for testing. With trigger depressed, I get 20.6V from brush connectors on motor PCB, end of bin, and end of wand so it's not an open circuit anywhere. Bench testing both heads on power supply, both brush heads spin so it's not bad heads. Accessed a brand new V8 for testing and my brush heads spin, so it's my V8 PCB that's the issue. PCB looks fine no obvious signs of damage. However I should not be getting 20.6V from the brush terminals without a head attached, correct? Brush heads are rated for 16.2V. I moved brush wires over to main lugs and both brush heads spin fine, although VERY fast due to the increased voltage. Perhaps an IC for the brush head supply is faulty and only remedy is to replace the motor/PCB. Should I mod the unit to give brush heads power from main lugs and call it good? What do we think?

DreWRX · « **Reply #1 on:** June 20, 2021, 07:14:45 pm »

Well, I went ahead and modded the unit to bring the brush head wires to the main lugs. All works well now, but I know this isn't the intended config or voltage the brush heads require. Would I possibly shorten the life of the brush head motor this way?

MVacs · « **Reply #2 on:** June 21, 2021, 01:47:11 pm »

I doubt the difference between 16 and 20v will matter too much.

But changing the motor unit would be the usual way forward.

DreWRX · « **Reply #3 on:** November 01, 2021, 04:35:19 pm »

Just wanted to post an update: The brushes spin normally now with brush wires jumpered to the main motor lugs. No issues and I'm not sure if the brushes are supposed to spin at the two selectable speeds for the main motor, but they do that now. High speed is pretty insane for the fluffy brush.