The Monitor Switch is an OEM replacement part for GE microwave ovens. Located internally on the turntable control circuit board, this switch monitors rotation of the turntable during cooking cycles.   Causes of failure involve degradation of the electrical contacts from continuous arcing loads over years of use combined with vibration stresses. Symptoms of a faulty monitor switch include: The turntable no longer rotates or spinning intermittently Cooking cycles aborting prematurely with error messages  Screeching or grinding noises emanating from beneath cavity Visible burnt spots on turntable drive assembly This genuine GE switch is also compatible with select Hotpoint and RCA models.WB24X830 (AP2024338) replaces 253820, AH237422, EA237422, PS237422, WB24X0800, WB24X0830, WB24X10075, WB24X800.