Hello,
A couple of weeks ago I heard my microwave making a noise, sounded like a fan was going up in RPMs and then down again. Might not have been a fan, could have been the magnetron. Anyhow, I went outside a few hours and came back in and my wife said the microwave made a "pop" noise and wouldn't turn on. The microwave was pretty hot as one can imagine.
I'm pretty handy when it comes to pretty much anything in or around my house. I took the microwave apart and the only issue I found initially was a blown thermostat fuse (likely the pop she heard). I ordered a fuse and put it in and got power back to the microwave LCD screen.
Once I had power back I noticed 2 issues:
My initial assumption was it's the circuit board because all of the buttons would work with the exception of the fan On/Off button. Ordered new board and issue is still present.
I tested all of the thermostat type fuses (4 of them I think) for continuity and they are good. I tested all ceramic fuses (2 of them on a small circuit board separate of the main board) and the door switches (3 of them) and everything tests good. I also tested the HV cap, magnetron and HV transformer and all of those devices test within spec.
So, what am I missing? Is it possible for a magnetron to test good and be bad or maybe the same for the HV cap. I don't think it's the transformer but at this point I am down to the big 3. And I'm not sure that any of those 3 would have an effect on the exhaust fan.
Could the issue be the small circuit board (it does have a copper coil and a couple other small soldered components). I'm not sure what that board's function is entirely, but I assume it servers to deliver power to particular components since it has the 2 ceramic fuses on it.
Any thoughts would be much appreciated.
A couple of weeks ago I heard my microwave making a noise, sounded like a fan was going up in RPMs and then down again. Might not have been a fan, could have been the magnetron. Anyhow, I went outside a few hours and came back in and my wife said the microwave made a "pop" noise and wouldn't turn on. The microwave was pretty hot as one can imagine.
I'm pretty handy when it comes to pretty much anything in or around my house. I took the microwave apart and the only issue I found initially was a blown thermostat fuse (likely the pop she heard). I ordered a fuse and put it in and got power back to the microwave LCD screen.
Once I had power back I noticed 2 issues:
- The microwave wouldn't heat.
- The exhaust fan (not the cooling fan) would not turn off. As long as the microwave has power, the exhaust fan turns on.
My initial assumption was it's the circuit board because all of the buttons would work with the exception of the fan On/Off button. Ordered new board and issue is still present.
I tested all of the thermostat type fuses (4 of them I think) for continuity and they are good. I tested all ceramic fuses (2 of them on a small circuit board separate of the main board) and the door switches (3 of them) and everything tests good. I also tested the HV cap, magnetron and HV transformer and all of those devices test within spec.
So, what am I missing? Is it possible for a magnetron to test good and be bad or maybe the same for the HV cap. I don't think it's the transformer but at this point I am down to the big 3. And I'm not sure that any of those 3 would have an effect on the exhaust fan.
Could the issue be the small circuit board (it does have a copper coil and a couple other small soldered components). I'm not sure what that board's function is entirely, but I assume it servers to deliver power to particular components since it has the 2 ceramic fuses on it.
Any thoughts would be much appreciated.