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Author Topic: Dyson DC40 brush bar  (Read 4453 times)

Offline RandyM

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Dyson DC40 brush bar
« on: February 18, 2020, 07:11:58 pm »
The brush bar on our Dyson vacuum has stopped working.  I have read through the Dyson forum but have not yet read a topic about our specific issue.  We are in the US and the vacuum is a Dyson DC40 120V 60Hz 10A with a model number of DN-US-DEC0716A.  I replaced the switches for both the motor and brush bar 18-24 months ago.  Two months ago I replaced the brush bar wiring loom.  The brush bar has stopped working again.

I checked the wiring loom and there is no break and connections were tight.  While checking the wiring loom I looked at the pcb and did not see any sign of burning or discoloration.  I’ve checked switches and they appear to be working correctly.  With the unit on and leaned back, I read 157VDC with a multimeter at the brush bar connection.  I have removed and disassembled the brush bar to fully clean it.  While I had the brush bar off, I applied 12VDC from a car battery (not in a vehicle at the time) to the brush bar motor terminals and was able to see the motor turn which would verify the motor was not burned out.

Are there any additional test or checks that I can do to determine why the brush bar will not work?

Offline ryevac

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Re: Dyson DC40 brush bar
« Reply #1 on: February 18, 2020, 09:42:18 pm »
I would say motor even though you have seen it rotate with 12dc - that is a red herring.
Alternatively - is the machine an ERP version ? i ask that as the (erp) version pcb is not as straight forward as people think, even if it does have a voltage of 157vdc present with no load (head not attached).
I believe an erp version control pcb will shut down if it sees a bad motor. Attaching 12dc from a car, bench power supply or battery will not see a bad motor.
The only way to fail is not to try.

Offline RandyM

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Re: Dyson DC40 brush bar
« Reply #2 on: February 18, 2020, 09:53:21 pm »
Thank you ryevac.  I do not know if it is an ERP version, and I am uncertain how to determine if it is.  That said, I think I'll get a motor to install. 

Offline ryevac

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Re: Dyson DC40 brush bar
« Reply #3 on: February 18, 2020, 10:23:06 pm »
If they did an erp version of this then it has a red manual sliding lever on front of the brushbar.
Am sure someone will correct me if not.
Also isn't the head motor same as the dc24 ? they are crap and don't last long. Some erp versions pcb can be damaged after using it with a bad head motor, people buy the new motor, fit it and then reveal that the pcb is damaged also.

With a bit of luck you are just suffering with the motor.
Just my opinion on diagnosis at a distance - i could be wrong !
The only way to fail is not to try.

Offline RandyM

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Re: Dyson DC40 brush bar
« Reply #4 on: February 18, 2020, 10:33:41 pm »
Again, my appreciation for the help.  The locking tabs on the bottom plate are red, but there is no manual sliding lever.  At this point I do not know if this is the same motor as a dc24 and unfortunately I do not have a model/serial number off the motor at hand. 

I have just spoke with a local shop that can supply the head (without roller brushes or bottom plate) for $70US.  Your caution about the pcb has me thinking this through a bit more before I purchase the head. 

Thank you.

Offline ryevac

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Re: Dyson DC40 brush bar
« Reply #5 on: February 18, 2020, 11:05:54 pm »
I had a look online and there are two versions, you have the non erp version by the sound of it.

Non ERP control pcb should be ok as i think it is just a few passive components, bridge rectifier, caps and resistors, these rarely fail i found.
You just need the non erp head motor in that case, i didn't actually realise there are two different motors for the head - or maybe i am just reading crap info online. I will have a look at stuarts (manchester vacs) page and see.
Pretty sure i always fitted the standard motor in the past on these whether it was erp or not.
The only way to fail is not to try.

Offline ryevac

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Re: Dyson DC40 brush bar
« Reply #6 on: February 18, 2020, 11:13:55 pm »
https://shop.manchestervacs.co.uk/dyson-upright-vacuum-cleaner-spares/dc40-spare-parts/dc25-dc41-brushroll-motor-johnson-dc771(2)xllg

It appears so, that an erp version must have an erp head motor fitted ?  possibly the dc 24 standard motor is the same as the dc 40 non erp motor.
Need Stu / david or someone else to confirm this please. I have just looked in my notes and i put a dc24 cross comp with dc40
The only way to fail is not to try.

Offline __russ__

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Re: Dyson DC40 brush bar
« Reply #7 on: February 19, 2020, 08:35:14 am »
The earlier DC40 had the same brushbar motor as the DC24 but the black connector on the end of the cable differs.

The later ErP version used the same brushbar motor as the DC25.

The earlier version had the grey brushbar and the ErP version is blue with the cleanerhead having a red slider on as ryevac says.

Offline ryevac

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Re: Dyson DC40 brush bar
« Reply #8 on: February 19, 2020, 09:27:51 am »
Thanks Russ, i couldn't remember exactly.
The only way to fail is not to try.

Offline RandyM

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Re: Dyson DC40 brush bar
« Reply #9 on: February 19, 2020, 01:50:15 pm »
I appreciate the insights.  After looking at the link describing the erp version, we do not have that style.  I will pull the head today and remove the motor to get numbers from it to order the correct replacement.  At least it’s only the head!

Offline ryevac

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Re: Dyson DC40 brush bar
« Reply #10 on: February 19, 2020, 03:30:54 pm »
Ok Randy, it should be same as the dc24, standard motor.
hopefully thats the issue.
The only way to fail is not to try.

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