Bosch Classixx 1400 Express, drum not turning but motor OK?

[HBR]

I tacked onto the end of another thread but mabye folk hav'nt bothered looking back there so I thought I'll stat a new one here!

My machine is a 2004 Bosch Classixx 1400 Express, & the fault is the drum wont turn, it turns by hand fine so I took the back cover off & the belt is on OK. Following that I thought a bit research was in order & found much talk of the motor brushes wearing out, many of the threads on this forum so here I am!
I've had the motor off & found the brushes to be good, plenty of life in them, no contacts, windings, commutator etc look or smell burnt, the thermal fuse checks out ok & I've cleaned out a lot of dust, including between the commutator segments. The motor turns fine & smooth in both directions but you can here the brushes moving over the commutator segments.
So I'm thinking this is going to be a problem elsewhere, any way I can check that the motor is good & that it's being supplied with what power it should when it should? When it's set to a spin cycle the pump runs to empty the water & there is something clicks like a relay to swtich the drum motor on but nothing happens. Really I suppose it finding out if it's practical to repair, the cost of getting someone to come out to a 6 year old machine will make it uneconomical I'm thinking.

Just so you know a bit about my ability I'm an Agricultural Engineer, so fairly adept at the mechanical stuff & 12vDC electrics but little beyond decent DIY level with 240v ac mains. Though I expect the motor here is DC when it has brushes?

Thanks for any help, I like the look of things in here, we've few repair/maintainance jobs coming up around the old farm buildings that I may need help with!
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[zipper]

Getting a bit confusing now. I have asked the moderators to delete the other posts.
To recap; Your motor is not DC...it is a universal type & can run on both AC & DC (almost all domestic appliance motors are AC powered). You could have a motor, wiring, or pcb fault. To find out which can sometimes be a little challenging. A good place to start would be to post the machine E-number on the door sticker.

 

[HBR]

Thanks for the reply, here's the number off the door:
E-Nr. WFO2866GB/01 FD 8403 601774

I did expect an AC motor but then I thought, it's got brushes so DC.

 

[zipper]

A couple of questions...
Does the door lock when you try to start a program? Does the pump run initially? Does the machine fill water? When you looked at the motor did you check if either of the brushes were sticking in their holders?

 

[HBR]

Yeah, the door locks & then remains locked as it should till a minute after it's finished, pump runs & it fills with water. Brushes in the motor were evenly worn, not sticking & are plenty long enough as while cleaning the motor out I put them back & in they protrude 6-7mm further into the motor than they can when in contact with the commutator.

I've checked along the wiring as much as I can to check for places looking burnt, worn through & being chewed by mice & cant see anything wrong.

There was a fair bit of dust in the motor though, would it be possible that would short & blow something on the controller? Would I be right in thinking the controller doesnt power the motor directly but works through relay switches so it doesnt handle the real power? That would mean the relay would be a likely problem if the motor is'nt getting power?

Anyway, what I've been thinking is if it's in the motor then it's not the brushes or the thermal fuse so likely a new motor job, & if it in the controller then it's not going to be a servicable part either & both motor & controller are going to be £150-200 which is too much to be spending on a 6 year old machine.

 

[zipper]

Apart from checking the motor winding resistances against manufacturers values (which doesn't always prove much anyhow) perhaps a helpful local domestic appliance workshop may be able to bench test the motor for you. It isn't something you'd be able to do at home unless you happen to have a variable voltage source at hand. With the field winding & armature hotwired in series they should be able to run it up to speed & load it to see how it behaves (& check the tacho output at the same time). If they green light the motor then your pcb is history....which at the end of the day is your most likely culprit I'm sorry to say

 

[HBR]

Well it's either motor or the control unit then, oh well, shopping for new machine by the looks of it! Thanks for your advice, not the result I want but thanks all the same!
The Bosch was meant to be a no-nonsence quality machine, 6 years is dissapointing as others have made it 10+ before it, have we just been unlucky or should we be looking at another brand?

 

[zipper]

To be honest its a lottery. Bosch (at least the German made ones) are usually pretty good mid range machines. Obviously not in the same class as Miele or ISE but pretty good all the same. If you read through the posts in this section of the forum you will see a pattern. Certain makes raise far more questions than others, but Bosch is nowhere near the bottom of the list. Miele & ISE are not common visitors to the forum, so either they are too expensive for the average household....or they just don't break down very often. Generally speaking reliability & machine life can be seriously affected by overloading, poor leveling, lack of maintenance, & sub-standard components. I believe manufacturers must bear their share of the blame by producing cheap appliances that are simply not up to the job. Consumers should be more critical...but it isn't always easy if like the rest of us mere mortals your budget doesn't stretch to a £1000 washer.