On 23/03/2019 6:37 am, Cursitor Doom wrote:
Hi all,

I have had the same Daewoo microwave oven since I bought it new 7 years
ago and it's always performed *perfectly* up until today. This morning I
stuck some bread in it to defrost and it came out still frozen. No trace
of any heat at all. The platter rotates, the light comes on, the timer
counts down, the fan runs; all is working fine except for the total
absence of heat.
I'm given to understand that microwave ovens typically have a working
life of only around 2 years nowadays, so I'd really like to fix this one
up rather than replace it with something inevitably inferior. Any
suggestions as to what to check for? I have the gear to measure up to
50kV if necessary, and I'd guess the magnetron HT is considerably less
than that figure. So... where to start looking first?



**First off: As Phil has stated, these things are VERY dangerous.
NOTHING like working on the EHT of a TV set (which certainly can bite).
2kV+ of DC WILL kill. No doubt about it.

Next: If it has a big ole' transformer (easy to tell, if you need two
hands to carry it), it should be an easy fix. Diode or magnetron. Most
likely the magnetron, though they usually fail slowly, due to emission
loss. It could be something else though.

Lastly: If it employs an SMPS, rather than a big lump of iron and
copper, dump it and buy a new one. Not worth the effort.


--
Trevor Wilson
www.rageaudio.com.au

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