[Steevmac]

What causes the HV Diode to fail? My XL1400 stopped heating over the weekend, suspecting the cap, the cap appears to function as normal when tested with a DVM, however the diode does not conduct when forward biased. Not having a schematic, what could cause the diode to fail, can the magnetron fail in such a way that it causes the HV diode to fail? I can throw a new diode on it but do not want to feed diodes if there is a possibility that something down stream could continue to cause them to open. Is there a bench test or voltage reading (have scope can also look at waveforms) I can perform for the magnetron? Prefer to logically replace items rather than shot gun. Thanks

[Gene]

The most common problem with "JVM" models for last 10 years is a faulty magnetron. So the chance it is bad in your microwave is very high and a bad diode is the first sign.

Gene.

[Steevmac]

Thanks for the quick response Gene. I popped the covers and found the schematic. Ordering diode and magnetron. As the cap is part of the same ckt. do you know how often he cap fails? Sounds like I am luck to have gotten 10 years of this one, it has been a good one so far.
Thanks

[Gene]

The capacitor usually lasts much longer and it is very easy to diagnose.

If the capacitor gone bad - it will cause an electrical short and blow the fuse.

Let me know how it goes.

Gene.