Replaced the magnetron, capacitor and diode (note all tested ok with DVM tests), suspect magnetron was bad regardless). Also using previously purchased parts, replaced the 3 door switches, the humidity sensor and the damper switch as the convection feature had been dead for many years (error code F5, microware is a 17 year old Kenmore Elite). After replacing all parts microwave heats and convection works again. Saved the $900 that a new (lesser quality) convection microwave would have cost and avoided the rework of the backsplash that it would have required due to different dimensions.