LG MB-387W Service Manual - Page 20

COMPONENTS FUSE TEST PROCEDURE Check for continuity of the fuse with an multi-meter. RESULTS Normal Abnormal H.V. FUSE NOTE: If the fuse is blown, check the primary, the secondary, and the monitor switches, H.V.D. and H.V.C. before replacing the fuse. If the fuse is blown by improper switch operation replace the defective switch and the fuse at the same time. Replace just the fuse if the switches operate normally. Check for continuity of the H.V.Fuse with multi-meter. Normal Abnormal HEATER ELEMENT (Wire leads removed.) Measure the resistance. (Multi-meter scale: Rx1) Normal: *Grill heater Approx. 38 ohm (at 20 ~ 30oC) Measure the resistance with 500V-100M ohm insulation resistance meter. Normal: more than 0.5 Mohm GRILL THERMOSTAT OVEN THERMOSTAT MAGNETRON THERMOSTAT NOTE: Make sure heater is fully cooled when tested. 0°C~Approx.90°C Approx.90°C 0°C~Approx.145°C Approx.145°C 5-10