This is a 25 yr old stove top. I suspect the problem is the spark module and want to confirm. All 4 burners electrodes have been cleaned. When I unplug the stove for a few minutes and plug back in it will spark for a few times. I want to check wiring to the spark module. Is removing the bottom cover with the stove top in place the best method ? I have removed all the cover screws, but found the cover very tight on the housing and did not remove it. Thanks.