Miele W5872 Fault F104 (low voltage to motor)

[barnesy1977]

Hello, I wonder if anyone could offer some advice please. I have a Miele W5872, 12 years old. Last week it stopped working during a cycle, producing fault code F104 "The mains voltage applied to the drive motor is too low". This happened several times in a row - even after turning the machine off for a long time. From researching, I believe this is usually the motor - given the age of the machine, it's understandable. I bought a second hand one from a reputable seller for £50, but unfortunately the error is still occurring.

Assuming the replacement motor isn't also faulty, the other possible option is the power supply to the motor. The main board (ELP 266 see photos) isn't that old as it was replaced in 2021, though I appreciate it could still be this. But I'm wondering if it could also be the smaller power control unit which has 2 relays (EZL250).

Does anybody have any insight into whether it is more likely to be one or the other, or if it definitely wouldn't be either one of those ?

If it's likely the main board, then we'll scrap the machine and buy a new one. Whereas the smaller power control unit are quite cheap to buy.

I appreciate it could also be a power supply problem from our main supply board at home (unlikely as the board and wiring is only 5 years ago), though we haven't had any issues or flickering from any other appliances/devices. I've tried the plug in a different socket, to rule that out, though it still on the same circuit as the other plug (which wouldn't rule out a faulty circuit breaker for example). I don't have the option to try a socket on a different circuit due to no water supply or waste in other rooms.

Many thanks in advance, David

[Whitegoodshelp]

Hello David. Yes I'm not surprised the replacement motor didn't fix it. My interpretation of, "The mains voltage applied to the drive motor is too low" is that the motor is not receiving the correct voltage. If you haven't done already, I would also check the connections and pins inside the motor plug and carefully check the wires in the motor harness right back to the PCB. To be honest, I don't know what that small PCB does. If the motor connections run to it than it may be relevant but if the motor connection drum back to the main board I would guess that it is controlled by the main PCB. This is likely to be horrendously expensive. Unfortunately, there is no information at all available for how to diagnose or repair washing machine PCBs.

[barnesy1977]

Thanks Andy. Yes I did think the same about it likely being a feed to the motor. But so many posts I looked at suggested the motor would normally be the issue here. I guess if the motor isn't demanding the voltage it needs (through a fault), then the sensor would also report that as low voltage, but wouldn't know why (ie whether it's a demand or supply issue).

I'll trace back the cables etc and if nothing is apparent, we'll just get a new machine due to the silly cost of replacement pcb's.

thank again for your help.

[Whitegoodshelp]

Hi. Motors don't ask for power they are totally just fed power. Good luck with checking.