Bosch Classixx 1000: Motor Suddenly not running

[richard3226]

Hi. I've had my Classixx 1000 about 21 years. Yesterday it successfully washed, but today the motor is not working. Because I found some remnants of a paper facewipe in yesterdays wash, I wondered (at first) if I had a drainage problem, but now I know the fault is simply that the motor has failed to run at all.  The wash program  actually starts and ends, i.e. I do not get a fault indication. During the program I can hear clicking that appears to come from the main circuit board. I surmise I'm hearing the operation of a relay. The drum spins easily and the belt is good. So, I'm wondering if anyone can suggest what the fault is. Is it likely to be worn brushes, given the suddeness of the appearance of the fault? Thanks.

Edited July 13, 2019 by richard3226

[Whitegoodshelp (Andy)]

Yes worn carbon brushes are number one suspect especially if they’ve never been replaced. It can be other things too but check them first. To be honest at 21 years it’s quite possible that the main armature in the motor is also worn. 

Read this article for further help  there’s a link to carbon brush diagnostics in it too

washing machine motor not running

[richard3226]

Hi. I've looked at the brushes and they are 1/2" in length. I think they will be seviceable, but I've gone and ordered new brushes.

I'm not sure if you can reset a Classixx 1000 model and whether this is an issue.  There is this, but not sure if it applies to my model:

* Turn the program dial to the off or reset position (should be at the 12 o'clock position)

* Turn the dial to the 6 o'clock position.

* Press and hold down on the spin button and simultaneously turn the dial to the 7 o'clock position.

* Hold the spin button for around 5 seconds and then release.

The spin button on my model might be the 1000/600 button. "(T)urm the dial to the 7 o'clock position" is a bit cryptic and lacks specificity!  Next postion on my model from the 6 o'clock position would be "Drain".

I may have to check the motor's thermal cut-out I suspect.

Edited July 15, 2019 by richard3226

[Whitegoodshelp (Andy)]

Hello Richard. I can't imagine resetting a washing machine can get the motor to run if the motor is not running due to a fault. Unfortunately if the motor isn't running it could be caused by at least a dozen totally different faults. In all honesty if the washing machine is 21 years old I'm not sure it's worth pursuing.  I'm surprised you've been able to buy any parts for it at all as most of them are very likely to be obsolete by now. Checking the motor's thermal cutout should be straightforward enough if you have a reasonable idea what you are doing. They are normally about half a dozen pins that you can check continuity for. There should only be the carbon brushes, the field coil and TOC to check. However, again, if the TOC has gone there is no guarantee hasn't gone because a more serious fault occurred on the motor. TOC's are thermal overload cutouts and only supposed to fail if the motor dangerously overheats.

[richard3226]

Hi. You know, I've always doubted that my motor is faulty. Because the previous wash it worked and the next wash not. No intermittent operation. In fact, I've managed to test rotor, stator and Tachometer and all test OK for continuity. The relays are operating and the cycle completes. It's looking to me that the motor not running is down to that shredded paper facewipe that I found in the previous wash.  I'll let you know if I manage to psche out the reason for motor not running. I have managed to aquire the washer circuit. Drains perfectly and tube to pressure swiich (filling up with water) is clear. Rich

Edited July 17, 2019 by richard3226

[Whitegoodshelp (Andy)]

Thanks Richard. An obstruction like a face-wipe could get inside the pump and stop it draining the water out. That could prevent it from doing the fast spin as a washing machine shouldn't spin with water inside. I can't imagine how it could cause the motor to stop running though. Not unless it somehow physically jammed the drum and seized it up.

[richard3226]

Hi. If I have it correct the picture shows a simplified circuit for the WFL2063GB/12 washer.  If I have not erred in selecting the right wire, there is no mains voltage to the rotor of the drum motor.  If that is the case, one has to explain how can a shredded paper face-wipe in the drum lead to the absence of mains to the rotor.  This is different from a problem affecting the signal to the triac, where it is more forseeable that this could be affected by a shredded paper facewipe. Remember, the program wash cycle does start, water enters and at the end is drained. Mains being AC.

Edited July 18, 2019 by richard3226

[richard3226]

Hi. There should be Live  AC mains on pin 4 of the side connector on the main board that connects all the wires to the drum motor. I've traced the cicuit back from pin 4 towards mains source and it looks there is a switch that Live mains must pass. I post a picture of the arrangement that is possibly faulty. Can you please tell me what it is?  Between 2 & 3 is a switch, but what is between 1 & 2? I think I may have a situation where we have a good situation between pins 1 & 2, but not pins 2 & 3. Thanks.

Edited July 19, 2019 by richard3226

[Whitegoodshelp (Andy)]

Hi Richard. Domestic appliance engineers don’t actually deal with circuits diagrams of the pcb. If the motor isn’t running we test the motor and the connections to it. If they are all ok and no break between the motor harness wires and the pcb connections it has to be the pcb. 

[richard3226]

I fixed the washer. It was (apparantly) a dry joint on the neutral side of the circuit shown above   As to that door interlock diagram I now understand that between pins pins 1  & 2 is the heater element (PTC thermister) which, when reaching a certain temperature, causes a bi-metal strip to close the switch contacts between pins 2 & 3.

[Whitegoodshelp (Andy)]

Thanks for the feedback. It's as I thought, if it's not the motor or any of the connections to it, then it has to be the pcb. Regarding the door lock, if there is a fault with that then the entire washing machine won't work (apart from the control panel). You might be interested in my article on How does a washing machine door interlock work?