I hope someone can give me some pointers here. I have an old washing machine, a Thor ST100X, which was working fine until recently. It must be at least 15 years old. When I select any program and put half a load of clothes, it works fine, but when I put a full load of clothes and select any program, the drum does not spin at high speed. Clothes are soaked wet. It looks like it's too heavy tfor the drum to turn at high speed whereas it used to work before. The strangest thing is that the button starts to move by itself (see video). To "solve" this, I have to unload some clothes and rerun the spin feature so clothes get dried.
If it's a brush motor, check the brushes. When they run out, the engine will rotate, but it won't have the right power and won't go into high speed. Check that there is no spark at the point of contact between the brushes and the commutator. With each start it will get worse and worse until it stops working - the brush will stop sticking, the tight "copper" power supply will not allow it. Salvation: replace the brush with a new one. Temporary rescue: you can solder this copper by loosening the tight copper, thereby ensuring the brush adheres to the commutator. After washing, buy new brushes and replace them. There is a probability of damage to the commutator when the brush wears even more and rubs against it with copper. And as for the rotating programmer knob, I am not speaking because I have not had such a case yet.