Use a spudger or your finger to firmly press the top of a sensor. You should hear a loud click, signifying that the metal strips in the sensor are flexing properly.

Repeat for the second sensor.

If you don't hear a click, the contacts may be fused together, or the metal springs are worn out. Skip to this step to clean or replace the sensor.

Sometimes, just flexing the sensors will fix the problem. Carefully re-assemble the pressure cooker and check if it works.

If the pressure cooker doesn't work, unplug the device, and follow the subsequent steps to further diagnose the problem.