Microwave capacitor

[daveaspy]

Our 26 month old (2 yr guarantee) microwave decided to stop heating this weekend, although it makes all the usual noises/sounds but power usage is only around 200W.

I've tested the HV diode ok, the HV transformer gets a supply when it should, but the big 1.0uF capacitor is reading (discharged and isolated) about 240uF on my multimeter. Is this likely to be a correct capacitance reading? I've read about caps going open or closed circuit, not so sure about having a high capacitance though?

 

[mattylad]

May not be anything to do with what your doing but best to watch this esp 9 minutes on.

Also:

 

[mattylad]

What are you measuring it with?

Have you an analogue meter?

 

[daveaspy]

I was using a digital Fluke multimeter with capacitance mode - unfortunately the replacement cap that just arrived also shows nothing like the expected value, they do have an internal 1MOhm resistor across the terminals so that might be screwing up the reading? The new cap doesn't resolve the problem so thats going back, looks like a problem with the HV transformer or magnetron then, that doesn't seem worth fixing

 

[mattylad]

Have a look at the videos of the first one I posted, he suggests several microwave faults.