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Posted to sci.electronics.repair
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GE Microwave JVM1540DM3WW Everything but Heat
Ian Field wrote:
"Trevor Wilson" wrote in message
...
On 4/4/2013 2:06 PM, wrote:
Everything operates correctly, except no heat. I can hear a transformer
hum, come and go while it acts like it is working, like it is trying to
run, but nothing heats. I understand electrical systems and have read
considerable about troubleshooting and repair. I just wanted to ask
before undertaking this task. Based on the circumstances with the on and
off hum, what do you think?
Thank you ...Ken
**Commonly, the fault is that the magnetron has failed. HOWEVER, as PA
mentioned, inexperienced people should NEVER attempt to repair a microwave
oven. Even after switching off, sufficient energy may be stored in the
main filter cap to kill a human.
Utter rubbish! - the mains filter cap is insignificant, its the hefty cap in
the doubler circuit that could be dangerous.
The transformer secondary delivers 2kV at enough current to guarantee
lethality, it can strike an arc to your hand through a cracked screwdriver
handle and kill you!
The capacitor in the doubler is typically 0.9uF - 1uF and can remain charged
upto some proportion of 2kV.
plus you need a good pair of leather gloves just to open them these days.
The sheet metal (foil?) they use, especially the stainless is unbelievably
sharp on the inner edges.
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