Microwave oven not heating on microwave setting

Microwave Repair
1

Please make sure to click on General above and select the correct appliance type first.

Brand:Hotpoint
**Model Number:**MP676IXH
Main Symptom:Microwave not heating
What happens & when:When i try to use the microwave function the turntable spins, the light comes on but the food does not heat. The grill function works and gets hot, the oven function works and the fan runs. Could this be a faulty diode, capacitor or magnetron?

Error Code (if any):
Parts or tests already tried:
Photos / video link:

2

This appears to be a UK model, so information is very limited for me. However, this could be a few things. Aside from the microwave not heating, does it sound like it normally does? If not, is it quieter or louder than normal?