Post by D.M. ProcidaMy microwave oven, now 15+ years old, blew its fuse yesterday.
It's a slow-blow fuse (T10 AL 250V P).
I'm going to replace it tomorrow, but how likely is it that whatever caused it
to go is just going to do it again straight away?
Daniele
Quite likely.
I am surprised the high voltage fuse didn't blow. That's what happened
to mine - the magnetron had an anode cathode short and had to be
replaced . That and a failure of the high voltage capacitor or the high
voltage diode are really the most common problems, and are trivial to
replace.
It is possible to remove the HT fuse mostly, and if the thing doesnt
blow the mains after that, there are only 5 components on the HT side
to check - the magnetron, the HT fuse itself, the diode the capacitor
and the HT transformer. If THAT goes you are in trouble with likely
magic smoke coming out.
You can check the magnetron off power by putting a resistance meter
between cathode heater and ground. Should be open circuit. The
capacitor you can use a resistance meter to see if the needle jumps and
then goes back to open circuit.
The fuse is obvious to test but the diode is not - its stacked diodes in
series and needs a few volts to turn on.
If the magnetro9n has gone its generally around 50% of the unit cost, or
more, (somewhere in the £30-£150 range) and you should consider
scrapping the unit.
Diodes fuses and capacitors are all sub £5.
Apart from that I found mine easy enough to fix, with the proviso you
absolutely dont want to power it up with the covers off.
All in all its not worth the faff for a sub £100 unit, but mine was a
£250 catering unit, and a £75 magnetron and a 90p fuse was in budget.
--
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man if he has not formed any idea of them already; but the simplest
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