Author Topic: Is this right? Testing DC24 Brushbar motor (Read 8454 times)

Burton · « **on:** January 25, 2016, 11:41:20 am »

Hi everyone,

It's been awhile since I did electronics at school and just wanted to check that I had the right idea here.
To check that the voltage the brushbar motor is receiving is 240v DC i should have the
Vacuum turned on -> Brushbar motor connected into the pcb and check like so?

beko1987 · « **Reply #1 on:** January 25, 2016, 02:27:11 pm »

I'd connect the multimeter to the pins on the PCB where the motor plugs into first, check for the juice there.

Dont forget to have the machine reclined too, as the brushsroll turns off via a microswitch when upright.

MVacs · « **Reply #2 on:** January 25, 2016, 04:27:17 pm »

The brushbar motor will receive about 330v DC. Despite what the label on it says.

Fhtur · « **Reply #3 on:** February 06, 2021, 01:06:47 pm »

Hi. I'm now to this forum and i have searched for info on the DC24 head motor and PCB but I'm still unsure which is faulty. I now have 5 PCBs from old machines and all have between 305v and 325v output to the motor but only one of them actually works the one motor I know is good. I assume the other 4 are faulty but just seems strange when the voltage appears ok. Also I have a few head motors and all test between 200 & 400 ohms. The resistance varies as I move the motor round. Does all this seem ok as I don't want to blow any more PCBs? Thanks

MVacs · « **Reply #4 on:** February 08, 2021, 12:44:22 pm »

Quote from: Fhtur on February 06, 2021, 01:06:47 pm

I now have 5 PCBs from old machines and all have between 305v and 325v output to the motor but only one of them actually works the one motor I know is good.

Check you are still getting full voltage at the motor per the first post above.

Quote from: Fhtur on February 06, 2021, 01:06:47 pm

The resistance varies as I move the motor round. Does all this seem ok as I don't want to blow any more PCBs?

That is normal.

macman · « **Reply #5 on:** March 07, 2021, 03:04:25 pm »

I've just got a DC24 in with my least favourite fault: an intermittently working brushroll motor. It was clogged up with dog hair around the gearbox and drive spindle, I've stripped it down, cleaned it and rebuilt. It's all moving freely now but the motor either stops after a few seconds, or won't start. When it does run, it sounds fine.
Is this most likely to be a failing motor, or the PCB? If I get 330V DC at the PCB motor pins, can I assume that is OK and it must be the motor failing, or is it possible for the PCB to also throw an intermittent fault?
There is no visible damage to the PCB.
Do the microswitches ever fail on these?

beko1987 · « **Reply #6 on:** March 07, 2021, 03:06:48 pm »

I'd say motor, if the pcb is supplying enough to make it spin at all I'd say its good...

I've never stripped a brushroll motor down before, usually when their dead I just replace them. Dodgy comm segment if it's going so far then stopping?

macman · « **Reply #7 on:** March 07, 2021, 03:37:20 pm »

Thanks. Sorry, I wasn't clear: I stripped down the motor/gearbox assembly to remove the doggy debris, I didn't actually take the motor itself apart. I usually find loads of hair under the brushroll pinion which prevents it rotating freely, but that isn't the issue with this one.
Going to test the PCB output next.

beko1987 · « **Reply #8 on:** March 07, 2021, 03:56:19 pm »

Aaah I see! Yea, stripping everything down to the motor is essential on them all, stripped a packed out Dc41 earlier!
Peer into the vent hole and look at the comm as you turn it slowly, might make it clearer.

macman · « **Reply #9 on:** March 07, 2021, 04:58:04 pm »

I tested the DC voltage at the PCB output pins and now getting a big fat zero. Also, the motor will no longer spin up at all when reconnected and with the machine reclined. So looks like the failing PCB has finally expired and I shall be needing a new one.
Never had to replace one of these before, only ever the motor itself.