Problem: The microwave oven cooks slowly or unevenly.
Solution: Check the voltage at the outlet supplying power. If it is lower than 115 volts, there is a problem with your electrical service or breaker. A bad turntable motor may also be the cause. To check it, turn the microwave over onto its top. Remove the bottom grill. Set the VOM to RX1 and remove one lead from the motor terminals. Probe the terminals. If the reading is infinity, then replace the motor. The magnetron and the wave guide may also be the culprits here. They need to be serviced by a professional.
Problem: The microwave runs but it's not cooking anything.
Solution: Check the thermal cutoffs for both the oven and the magnetron. The thermal cutoffs are little disc shaped devices with a wire connecting the two of them. Remove a lead and set the VOM to RX1. Probe the terminals and look for a reading of zero. If not, replace. Check both thermal cutoffs. If these are OK, check the capacitor and diode as described above. The magnetron or transformer could also be bad, but they need to be serviced by a professional.
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Microwave Oven Repair 101Notes on the Troubleshooting and Repair of Microwave Ovens
