My gas oven will not turn on in bake or broil mode. Since it is apparent that the control buttons and gas lines are working, my first guess would be the ignitor has weakened to the point where it is no longer able to send a signal to light the burner. The ignitor needs to be taken out and tested for continuity.
Step 1: Safety First
Pull your oven gently from the wall. Shut off the power by unplugging it and then turn off the gas.
Step 2: Gain Access
Remove the racks inside the oven and take out the bottom plate. The bottom plate is generally screwed down inside to the base of the oven in the corners. My particular oven has two hex bolts in the back corners, then I have to lift the back to an angle that allows me to slide the front lip backwards then up. This will expose the bake burner and ignitor.
Step 3: Remove Ignitor
The ignitor is located in the back on the bake burner and has sensor wires that run below or behind the oven cavity. Unclip the plugs by either removing the broiler drawer below or the back wall, then remove the ignitor by unbolting the ceramic bars metal shield from the bake burner.
Step 4: Come to TechShop San Francisco
Bring your ignitor to TechShop San Francisco. As a member you can check out a multimeter from a staff member to test your ignitor. Power your multimeter on and set to the lowest setting for ohms of resistance.
Step 5: Test for Continuity
Take one probe and place on one terminal, then place the other probe on the second terminal. If there is continuity, your multimeter should register between 0-1100 ohms. If your multimeter does not register in this range then your ignitor has lost continuity and needs to be replaced.
Like mine does.