Simmer burner (left rear of stove top) was not working at all. Continuity of both the burner element and burner dial control checked good. Determined power was not getting to switch. This inline, supply side board seemed to be blocking power from getting to switch no matter if simmer button was pushed on or off. It sounds like there is a mechanical relay on the board as you can hear a click when you press simmer button but again no power was passing through to dial control. Took a $50 chance, replaced the board and the burner now works great with full fine adjustment simmer functionality.