If a microwave's glass turntable cover is broken, it is not recommended to use the microwave, even on lower power settings. Here's why:
Safety hazards: The turntable cover is designed to protect the interior of the microwave from spills, splatters, and potential damage. When the cover is broken or missing, there is a risk of liquids or food particles getting into the microwave's mechanical and electrical components, which can lead to malfunctions, electrical hazards, or even fire.
Uneven heating: The turntable cover helps distribute the microwave's energy evenly across the food, promoting uniform heating. Without the cover, the energy distribution may be disrupted, resulting in uneven cooking or heating. This can lead to hotspots and potential foodborne illness if bacteria or pathogens are not properly eliminated.
Shielding and containment: The turntable cover also serves as a barrier, containing any potential splatters or messes within the microwave. Without the cover, liquids or food particles may escape onto the microwave's interior, making cleaning more difficult and potentially causing damage to the microwave over time.
It's best to avoid using a microwave with a broken turntable cover until it is replaced or repaired. Contact the manufacturer or a qualified appliance repair professional to obtain a suitable replacement part or to assess and fix the microwave.