Magnetron

Magnetron

Geoffrey from PA

Microwave stopped heating.

#2 Phillips head screwdriver, pliers and multimeter

Dismantled microwave and checked components using the multimeter. I determined that the HV fuse was blown and the Magnetron had a low resistance (70 ohms) from the cathode to ground. Replaced the fuse, still no heat so I replaced the Magnetron which fixed the problem. The Magnetron is warranted by LG for ten years but failed at three. Good luck accessing the LG warranty; it will cost you more than just fixing the appliance at your own expense. Repair time is to fix the appliance. Since this is an OTR microwave allow another hour to remove and re-install above the range. This is a two person operation. Be very careful to allow the HV capacitor time to discharge or short the terminals together and to ground with a well insulated tool before working on the circuit.

Magnetron

EMMANUEL from IN

Whirlpool OTR Microwave oven was not heating after changing out a burnt fuse. Looked for cause of the bad fuse. Always look for what caused a fuse to go bad; although sometimes they just age and fail. Tests revealed HV Diode was bad. Magnetron looked toasted but resistance b/w terminals tested ok. Changed both Magnetron and Diode, and BINGO Microwave oven heats up fast like a bad MF.

Need a high voltage and Resistance Auto Range DVOM to diagnose. That way you wont have to F with low, high, settings, etc. Videos on Youtube very handy to help with required tools including special hex screw set with holes in their ends. WARNING!!! MW ovens retain very high voltages. Know what the F you are doing before you open the casing. Discharge the HV Capacitor PROPERLY!!! VOLTAGES can range b/w 4,000 to 5000 Volts. It can kill. Never use two hands on the high voltage side (Transformer, HV Diode, Megatron, etc. Always disconnect AC plug from wall before starting, and discharge Capacitor everytime you do a live run test on any component inside the oven. Be vigilant and CYA.

See above. Good luck. Keep a track of where everything goes, draw pics, label screws, make notes, use cell phone to record, and to show how things are positioned before dismantling. Be organized. Once you know all the steps, and have all the tools, it's easy, but don't let your safety guards down. Clean inside the casing while it is open.

Magnetron

John from IL

Bad Magnetron

Screwdriver

Easy repair, took less than an hour