Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!ubc-cs!alberta!calgary!ctycal!ingoldsb
From: ingoldsb@ctycal.COM (Terry Ingoldsby)
Newsgroups: sci.electronics
Subject: Re: Microwave Oven Repair
Summary: Diodes do die
Message-ID: <461@ctycal.UUCP>
Date: 14 Sep 89 18:51:55 GMT
References: <10931@fluke.COM> <14551@haddock.ima.isc.com> <10979@fluke.COM>
Organization: The City of Calgary, Ab
Lines: 28

In article <10979@fluke.COM>, inc@tc.fluke.COM (Gary Benson) writes:
> Apparently the diode was the only part that fried, and a couple of people
> indicated that what I had was a typical failure mode. But the replacement
> charge was obscene: 19.95 + tax!! sheesh! One guy told me it is about a
> 1 amp 6 kV PIV part, so if I ever have a need to fix this beast again, I'll
> look for "non-authorized" replacement parts!

Every microwave oven problem I've ever encountered involved either the
stack diode going bad, or occasionally the mixer (a little fan blade
affair that rotates above the cavity) getting stuck.  The stack diode is
subjected to very high voltage, and they do tend to deteriorate.  Since
they are essentially a series string of diodes, when one diode goes bad
(shorts) the others bear more and more of the burden until it finally
goes south.
> 
> Through all this, I also located the original sales receipt and owners
> manual, and learned that the magnetron carries a *10 YEAR* guarantee. Does
> anyone know why they offer such a thing? Don't magnetrons break or something?
> 
There is not much inside a magnetron.  I've never heard of one going bad but
I will ask a friend who works in a repair shop.



-- 
  Terry Ingoldsby                       ctycal!ingoldsb@calgary.UUCP
  Land Information Systems                           or
  The City of Calgary         ...{alberta,ubc-cs,utai}!calgary!ctycal!ingoldsb