Kitchen Aid Washer

My washer will fill to proper levels but will do nothing after that. No agitating, no spinning, no draining. I have checked the lid switch and it is fine. Checked the drive coupling and it appeared to be fine. That was the last thing i did before I put all but the cabinet back together. Tried it again and it worked fine. Spinning like a top! Put the cabinet back around and tested again. Started to work and then went back to doing nothing. "Nothing," as I say it, means performance. There is a buzzing sound when the lid switch is pressed and the washer isnt performing. The buzzing will presist for about 30-40 sec and then it will go away. Any help would be greatly appreciated.

Thank you,
jwd03004