Dyson & Sebo Vacuum Cleaner Repair & Advice Forums

Dyson Models => Second Generation "The Ball" Dysons. => Topic started by: Brookleigh on July 31, 2020, 12:38:13 PM

Title: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: Brookleigh on July 31, 2020, 12:38:13 PM
Hello All

The brush bar on my DC50 stopped rotating even though there were no obstructions on it, i.e. could turn by hand freely. I took it apart but could find no issues, although the motor appeared to be open circuit (>1 Meg). Anyway, I bought a brand new complete brush bar from Dyson and it does not turn either. I can see around 310V DC at the connection point to the brush bar when the main motor is running.

Any ideas what could be wrong? I was working on the assumption that the PCB is working OK otherwise there would be no DC voltage present.

I am new to vacuum cleaner repairs (at this level) so would welcome any help. No reply from Dyson by email or phone at the moment btw.

Thanks.
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: MVacs on July 31, 2020, 07:50:31 PM
I bought a brand new complete brush bar from Dyson

Do you mean brush roll or the full cleaner head?
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: Brookleigh on July 31, 2020, 07:59:31 PM
I replaced the full cleaner head assembly. It is the brush roller that is not rotating.
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: ryevac on August 01, 2020, 04:10:20 PM
Strange, but theoretically if you have the head dc supply voltage present but the head motor doesn't turn - then you would suspect the head motor.
But you have fitted new....

so, either new head unit is at fault (unlikely)

incorrect head ? is there more than one type for that model ?

or, you have a voltage present ( 310vdc ), however you are i suspect reading this voltage off load - i.e with no head connected....  i suspect if you measured this voltage on load (with head connected ) that the voltage will drop to zero indicating a fault on the pcb also.

In many cases with motorized head units it can be chicken and the egg diagnosis, and in many of them cases a failed head motor will also destroy it's drive pcb.
On these later vacs, the drive pcb's are a little more complicated than old dc24,25 models - dc40 onwards (erp versions especially) will not forgive a knackered head motor as often, and usually destroy the pcb drive.
Non erp versions are a crude rectifier, capacitor and a couple of resistors etc, and will forgive abuse.
I would in this case, again confirm voltage is there with no head connected, then connect the head and measure the voltage - it can involve stripping the head or ball assembly to get access to the wiring.
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: Brookleigh on August 02, 2020, 12:48:46 AM
Thanks for the advice.

I checked with the brush bar connected and you were correct - the DC voltage all but disappeared, so it looks like the previous brush bar motor took out the drive as you suggested. Is the next stage to replace the PCB?

Where is the best place to source one? The number on it is partly obscured by a red stamp, but it is something like 206206, followed by either a space or another character, then 01/03, and underneath the numbers is "dyson ERP".

Thanks again.
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: MVacs on August 02, 2020, 08:47:59 AM
965086-01 is the part number for a DC50 ERP PCB.
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: ryevac on August 02, 2020, 01:05:27 PM
Good work, as well as confirming the 310vdc disappears i would also check that the 240v ~ supply voltage to the pcb is still present at this stage.

I mention this as i have seen earlier ball models, where the cut out switch was partly burnt out and failed on load.
If 240v~ still present then it should be the pcb.
Ensure you are happy with yoke cable etc.
I suspect you are ok with working with mains voltages, but take care poking around...

The DC 50 i haven't really worked on a lot, but the principal design is almost the same regarding the head motor drive circuitry.
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: beko1987 on August 10, 2020, 12:23:22 AM
I've got a dc50 in with the same issue right now actually! It blew another pcb that  I bought and fitted so I'm assuming the issue is in the brushroll motor.
Need to price up a replacement tomorrow thinking about it. Half hoping he says no so I can see if the suction motor fits a shark...
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: beko1987 on August 10, 2020, 12:23:55 AM
Also have you stripped the thing down to access the pcb? It's not a pretty job, the wheel assembly has to come off
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: Brookleigh on August 10, 2020, 12:36:09 AM
Thanks for the advice. I replaced the PCB and it worked perfectly. I believe that the old brush bar motor failed short cct and took out the PCB drive. If I had replaced the PCB first, the original brush roller motor would have blown that as well (cost about 30).

Thanks again.
Title: Re: DC50 - BRAND NEW BRUSH BAR WON'T ROTATE
Post by: ryevac on August 10, 2020, 01:09:42 AM
 :thumbsup: