My kenmore 80 series will fill and then agitate, but then won't spin, It will make a low hum sound. If I open the lid and close it, it will start to spin. if i open it again and close the lid, sometimes it won't start to spin again. I have used a screwdriver to pin the door latch, but it still does the same. Also, if I turn the knob to the next spin cycle setting, it will start to spin. Any suggestions?