I did all those things, too, and it kept doing it....
Pack it up and carry it around in your car for a week. THen, give it to your friends to carry around in their car. Take it inside WM twice. Then, bring it back in, sprinkle a little fairy dust around it and make sure to cuss it about 100 times throughout the week.
Seriously, I did this. Mine works OK now, for some stupid reason. See my post about fed up with feed dogs.....(to get the whole story).