I have a hunch the microwave panel is going into Child lock mode and preventing you from operating the clear/off function. Not sure which is the middle switch that you replaced. I would suggest you give the panel a good wipe with a clean damp cloth to remove all grime etc. Before selecting the start/pause button press the Clear/off button for 3 secs and see if the L (lock) shows up on the display. Next press again for 3 secs to see if L goes away.
This way you have confirmed the panel is not in lock mode before you start next operation. Provide your observations in the comments section so that I can assess what the next step should be.
Answers & Comments
Chuck it in the bin
I have a hunch the microwave panel is going into Child lock mode and preventing you from operating the clear/off function. Not sure which is the middle switch that you replaced. I would suggest you give the panel a good wipe with a clean damp cloth to remove all grime etc. Before selecting the start/pause button press the Clear/off button for 3 secs and see if the L (lock) shows up on the display. Next press again for 3 secs to see if L goes away.
This way you have confirmed the panel is not in lock mode before you start next operation. Provide your observations in the comments section so that I can assess what the next step should be.