I tested the door latch & the start button to see if they were working , I did this by taking the top back panel off , then I closed the door & put the plug back in , then I turned the timer & heat control dial to a on setting then I pushed the on button and you could here and see the timer was working ! The timer has a small sight glass that spins when it's on ! But the control knob was not engaging , so I took the control knob apart , this is when I found that one of the three washers was cracked , These washers engage all the electric points in the control knob ! So I ordered the parts , and they arrived in a day in a half , fast ! It took all 25 minutes to in stall the new control switch ! I also bought a new power button , did not need it , but I'll keep on the shelf !