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My GE Profile Spacemaker 2.0 started to hum a bit louder and now makes no heat. I followed the GE troubleshooting flow-chart and it points to the magnetron, but the resistance checks (continuity pin-to-pin, open pins-to-case & no sign of any arcing or cracks in magnets). The HVT (hi volt Xfmr), Cap (capacitor) Xfmr, and diode all seem to be okay although my cheaper DVOM shows diode open both ways .. so I used 12v battery with 1.8k resistor in series & get 3.1v one way and 4.3v in other. The new diode that came with a new magnetron had same readings but this magetron was returned .. was wrong # and mounting pattern. So .. my unit draws about 5amps when mag is connected and about 8amps when mag is disconnected. Why more amperage when magnetron isn’t connected ? Does this mean anything to anyone ? What should I do next ? I appreciate any help, thanks.
It seems like your diode is bad. You say your cheaper DMM reads the diode as open in both directions, and then say it passes voltage in both directions. These are two opposite scenarios, but either is a bad diode. You should have continuity (i.e. closed) in only one direction. If you have continuity in both directions the diode is shorted, and is defective. If the diode does not have continuity in either direction it is open, and is defective. Plus, your battery test should only pass voltage in one direction - the other direction should be 0.0 VDC. Replace the diode and see if this solves your problem. Here is a site that explains the process. https://www.partselect.com/Microwave+tes… Update 5/14/18: Given that the 9v test measured voltage in one direction but not the other, indicates your diode is good. The voltage drop of the diode is most likely too great for your DMM to take a measurement. You component test chart even states, “Some inexpensive [meters] may indicate infinite resistance in both directions.” So accept the 9v test. So now I’m assuming your question is that even though the troubleshooting flow chart is recommending you replace the magnetron, your individual test of the component checks out good, so which is it. Most likely you have a short in the magentron (causing the humming). Try this: when measuring filament to chassis, tap on the magnetron to see if you can get it to show an intermittent short. The other explanation is the short happens only when the filament heats up during operation, but you don’t want to test a live magentron. You have already performed all the tests you can on the diode, HVC and HVT. They could still be bad (like a short between the windings of the secondary), but you do not have a accurate way of measuring them. The other check you can do is the wiring in the high voltage circuit. Check for burnt terminals, discolored wires, etc. Otherwise, I would replace the magnetron first, and see if this solves the problem. If not, next replace the HVC and diode. If this still doesn’t solve the problem, replace the HVT.
Hi, Check th HV cap anyway, some have an internal diode and they tend to short completely sometimes.
i would check your hv cap.
My GE hv diode measures open both ways in diode mode fluke 76 the oven buzzes an unusually loud audible 60 hz so i stopped usage web says replace diode part GE WB27X1160 so ordered online do you think the magnetron tube is the culprit? the model JNM7196SK3SS built March 2019 the needle nosed pliers handle grips coated still allowed capacitor dc stored charge to jump into me empty as a float so an insignificant amount of current to equalize i zing ed me - so i sleeved on tygon hose to insulate objective short out capacitor Update (10/22/2022) Can tube fail factory fresh using only 2years? Update (11/26/2022) Maybe the engg design to overly protect personnel from electrocution & irradiation burn incorporates sequential & coincidence interlocks that actually promotes failure by interlock (s) breakdown - the utility line power is intentionally cutoff from these parts creating oven irradiate whenever interlock(s) coincident are violated
Sorry I don’t know how to assess your capacitor behavior. Mine was also weird as you may have read. I never did learn if those odd readings were due to my cheapo meter or what. Be careful ! Replacing the magnetron definitely solved my problem and she continues to work fine today 4+ years later. It was a bit of a chore since mine is over stove / under cabinets. I hope you have similar positive results. I think that’s the culprit when you hear the loud buzzing - yes. G’luck, Ron
