My washing machine stop functioning when the knob moves to the drain position.

I don't know what brand you have, but see this: https://dl.dropboxusercontent.com/u/8010163/Understanding%20automatic%20washer.pdf
If we knew what brand you have you could get the manual(s).

I don't know what brand you have, but see this: https://dl.dropboxusercontent.com/u/8010163/Understanding%20automatic%20washer.pdf
If we knew what brand you have you could get the manual(s).

Thank you for the valuable materials. I have resolved my problem by detaching hoses from the drain pump and found that the pump was clogged. After having the debris removed, it ran perfectly.