"Trevor Wilson" wrote in message
...
On 4/9/2013 7:11 AM, 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.

**I said:

"...the MAIN filter cap..." Not MAINS filter cap (whatever that is). I did
not assume a SMPS, rather a linear supply. The cap in question can store
several kV.

And what gave you the idea of calling the voltage doubler charge-pump cap; a
"filter cap"?

Ian Field wrote:


"Cydrome Leader" wrote in message
...
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.


VCRs were just as bad before they started making *EVERYTHING* out of
plastic.

yeah- within the past month I cut myself on a circa 2000 hitachi VCR from
a storage room. I popped the cover to check the rubber parts which are
actually intact, and the takeup torque is still good.

I wonder who set the trend of "let's save money and leave sheared edges
razor sharp" on stuff like that. They need a solid punch to the face, over
and over again.

William Sommerwerck wrote:
And they're perfect for bacon. The microwave oven
is the bachelor's friend.

I always found microwave bacon creepy.

You mean it moves?

You're probably not cooking it enough. You can "blast" it in a microwave
without burning, if you so desire.


Did you have one of those weird "browning dishes"
with the metal oxide coating?

No, I never did. Are they still made?

nope, and they're expensive on ebay.

I don't want one, but it would be fun to play with for about 10 minutes
I'm sure.

frozen potpies have paper bowls now instead of foil that will brown stuff,
sort of like whatever the stuff is inside a bag of microwave popcorn.

Frozen potpies have paper bowls now instead of foil
that will brown stuff, sort of like whatever the stuff
is inside a bag of microwave popcorn.'

It's a ferrite, and called a "susceptor".

http://en.wikipedia.org/wiki/Susceptor

On 4/10/2013 12:34 AM, Ian Field wrote:


"Trevor Wilson" wrote in message
...
On 4/9/2013 7:11 AM, 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.

**I said:

"...the MAIN filter cap..." Not MAINS filter cap (whatever that is). I
did not assume a SMPS, rather a linear supply. The cap in question can
store several kV.

And what gave you the idea of calling the voltage doubler charge-pump
cap; a "filter cap"?

**Pedant.

I will say once mo

I did NOT say "mains cap", despite your mis-reading of my words.

You can back-track all you wish. The meaning of my words is clear enough
to any sane person.

--
Trevor Wilson www.rageaudio.com.au

William Sommerwerck wrote:
Frozen potpies have paper bowls now instead of foil
that will brown stuff, sort of like whatever the stuff
is inside a bag of microwave popcorn.'

It's a ferrite, and called a "susceptor".

http://en.wikipedia.org/wiki/Susceptor

I may have to spend the dollar on a potpie to take a look at the bowl. I
don't recall them looking or feeling all that special, but it was
fascinating that they did work.

I may have to spend the dollar on a potpie to take a look
at the bowl. I don't recall them looking or feeling all that
special, but it was fascinating that they did work.

They're best-known for their inclusion with Hot Pockets, but I find they don't
work that well -- probably because the sleeve surrounds the Pocket too closely
to allow moisture to easily escape. I generally start Hot Pockets bare in the
microwave, then crisp them in the toaster oven.

"Trevor Wilson" wrote in message
...
On 4/10/2013 12:34 AM, Ian Field wrote:


"Trevor Wilson" wrote in message
...
On 4/9/2013 7:11 AM, 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.

**I said:

"...the MAIN filter cap..." Not MAINS filter cap (whatever that is). I
did not assume a SMPS, rather a linear supply. The cap in question can
store several kV.

And what gave you the idea of calling the voltage doubler charge-pump
cap; a "filter cap"?

**Pedant.

I will say once mo

I did NOT say "mains cap", despite your mis-reading of my words.

The only thing I missed was the absent "s" on mains - as you called it a
filter cap, the interpretation was automatic.