Sensor error message - not heating food

Microwave Repair
,
1

I’m sure this is an oft-repeated question, but my GE JVM1750SMC02 works perfectly fine – except it doesn’t heat the food anymore. Round and round the food goes, but it gets no warmer. Neither time cook nor sensor reheat modes work. When I open the door from operating in sensor reheat mode, the panel shows "sensor error."

  1. Is it really the sensor? How do I know for sure?
  2. If it is the sensor, how difficult/time consuming is the replacement procedure?
  3. Is the sensor still covered under a parts warranty? If so, how do I claim the part under the warranty?

Thanks in advance.

Paul