LG LMVM2277ST Product Training Manual page 89

Magnetron Test
To test the magnetron, remove the connector to take it out
of the circuit.
Measure the resistance between the following points:
Meter scale Rx1
Filament terminals
Meter scale Rx1000
Filament to chassis Normal = infinity
LMVM2277ST
> 1 Ω
89
T-27