This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g., JMC1116AB)?

In article ,
"Danny D." wrote:

Having never worked on a microwave, I ask what the conventional wisdom is.

Probably just needs a new thermal cutoff. This random page has a picture.

http://sell.lulusoso.com/selling-lea...hermal-cut-off.
html

You should find a schematic inside the unit after you take off the
cover. With some basic electronic troubleshooting skills you can
identify which of the 2-3 thermal cutoffs has gone bad. They're cheap
and generic, but come in different temp ranges.

(Now, have fun turning this thread into a 500 post thread, while all the
helpful people teach you how to read a schematic and use your
multimeter, and arm you with enough info to write the internet's most
definitive treatise on microwave oven repair.)

On 12/17/2012 11:04 AM, Danny D. wrote:
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g., JMC1116AB)?





Looks like less than 2 feet to me. For something other than a fuse I'd
just replace it.

FWIW: Panasonic makes a really good microwave. "Invertor" 1300W. But I
think you need one that's insulated to protect it from the heat of the oven.

On Dec 17, 12:04*pm, "Danny D." wrote:
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
*http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting for
when it doesn't heat. They said the magnetron may need to be replaced:
*Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
*http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
*"May be built into a cabinet structure, but not for use adjacent
* to (with 2 feet of) any gas or electric range, cooktop or oven."
*http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
*This microwave is approved for mounting directly over Jenn-Air
*wall ovens as follows:
*W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom is..
Q: Is it generally feasible to replace just the magnetron?

Technically, probably yes. But, there are some obvious
problems. One is, there are a lot of things that could cause
it to stop heating, only one of which is the magnetron.
Figuring out which it is, unless you have the suitable
skills, schematics, etc will require a tech, service fee, etc.

The second is that if it is the magnetron, what does a new
one cost? Could very likely be buckoo bucks. Generally,
given the cost of a new regular microwave, it's not worth
screwing around with. But since this is part of a built-in
JennAire, I feel your pain.



Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?

I think that's unlikely. If it were that simple, could mix
and match other companies products into that JennAir
frame. For some odd reason, JennAir doesn't want you
to be able to do that.....


Q: Is it generally best to stick within the same brand? (e.g., JMC1116AB)?

I had an even older JennAir oven/microwave combo.
I did a mini makeover of the kitchen and got rid of it.
It was still working, but was outdated. So, I found a
Kitchenaid double oven on Ebay. It was a floor model,
but in perfect condition except for some sale stickers.
That unit retailed for $3000. I got it for $1200. It was
also a 30", which is a good thing, where the existing was 27".
I had to carefully scope out the cabinet situation where
it was going. And I had to cut apart the cabinet to make it
fit. Including taking the cabinet from above to a cabinet
shop and having them cut several inches off the bottom.
But it came out great. Looks 1000% better.

I also like the idea of double ovens a lot more than the
built-in microwaves. The look much nicer, are a selling
point for kitchens today. And from what I have seen,
the microwaves from the major kitchen appliance/oven
manufacturers cost $1000 and suck compared to the
$100 countertop model. They tend to be no larger,
more confusing controls, don't heat as well. If the $100
one goes, you just buy another.

Just some things to consider. Maybe you should buy
a countertop one and look for a great deal on a new
double oven.....

On 12/17/2012 11:04 AM, Danny D. wrote:
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g., JMC1116AB)?





If you do replace it, I'm pretty sure you can find a replacement trim
for your opening. That way you don't have to worry about the exact size.

I know Sears and Lowes sells them. HD probably does too.

On 12/17/2012 9:19 AM, Smitty Two wrote:
In ,
"Danny wrote:

Having never worked on a microwave, I ask what the conventional wisdom is.

Probably just needs a new thermal cutoff. This random page has a picture.

http://sell.lulusoso.com/selling-lea...hermal-cut-off.
html

You should find a schematic inside the unit after you take off the
cover. With some basic electronic troubleshooting skills you can
identify which of the 2-3 thermal cutoffs has gone bad. They're cheap
and generic, but come in different temp ranges.

Check fuses and electrical connections. I had one where corrosion
eventually overheated the connection on the door switch and disabled
it.
I've fixed a few microwaves, and almost all had bad diodes.
Certainly possible, but I've never seen a bad magnetron.

Be aware that the big cap can hold enough charge to kill you
after days and days being off.
Even if you don't get electrocuted, you can be seriously injured
when you fly across the room and bang your head on the counter.
And you'll be scraping pieces of skin off the sharp edges of the case.

I don't know of a good DIY way to discharge the cap. I once made the
mistake of shorting it with a wire. Scared the crap outa me when
the wire exploded.

I agree with Mike: use common sense and due caution. I've fixed many
microwaves and never seen a dead magnetron. Diode [cheap] has been the most
common failure. More irksome is a dead control panel. [I have a 30 year old
Toshiba going strong with a sturdy dial timer.] I'd stay away from the
Panasonic "inverter" models as there is no reason [unless you care about
weight savings from not having a heavy transformer] to over-complicate these
simple circuits with an inverter.

"gonjah" wrote in message
...
On 12/17/2012 11:04 AM, Danny D. wrote:
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting
for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom
is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g.,
JMC1116AB)?





Looks like less than 2 feet to me. For something other than a fuse I'd
just replace it.

FWIW: Panasonic makes a really good microwave. "Invertor" 1300W. But I
think you need one that's insulated to protect it from the heat of the
oven.

On 12/17/2012 1:28 PM, John Keiser wrote:
I agree with Mike: use common sense and due caution. I've fixed many
microwaves and never seen a dead magnetron. Diode [cheap] has been the most
common failure. More irksome is a dead control panel. [I have a 30 year old
Toshiba going strong with a sturdy dial timer.] I'd stay away from the
Panasonic "inverter" models as there is no reason [unless you care about
weight savings from not having a heavy transformer] to over-complicate these
simple circuits with an inverter.


Could be. I'm not sure what the inverter does. I've been using mine
daily for over 7 years now. It does have quite a few options.





"gonjah" wrote in message
...
On 12/17/2012 11:04 AM, Danny D. wrote:
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting
for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom
is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g.,
JMC1116AB)?





Looks like less than 2 feet to me. For something other than a fuse I'd
just replace it.

FWIW: Panasonic makes a really good microwave. "Invertor" 1300W. But I
think you need one that's insulated to protect it from the heat of the
oven.

On 12/17/2012 11:28 AM, John Keiser wrote:
I agree with Mike: use common sense and due caution. I've fixed many
microwaves and never seen a dead magnetron. Diode [cheap] has been the most
common failure. More irksome is a dead control panel. [I have a 30 year old
Toshiba going strong with a sturdy dial timer.] I'd stay away from the
Panasonic "inverter" models as there is no reason [unless you care about
weight savings from not having a heavy transformer] to over-complicate these
simple circuits with an inverter.

Inverter should let you have continuous power control.

I cheaped out when I replaced mine and didn't get an inverter. I regret
that decision.

It has 3X the power of the old one. And the 15-second on-time is
way too long for power regulation on small loads.

On Mon, 17 Dec 2012 09:19:35 -0800, Smitty Two wrote:

Probably just needs a new thermal cutoff.
I found only one so far - and it checked out at 0.5 ohms:
http://www3.picturepush.com/photo/a/...g/11712046.jpg

You should find a schematic inside the unit
Found it. Thanks!
http://www3.picturepush.com/photo/a/...g/11712051.jpg

arm you with enough info to write the internet's most
definitive treatise on microwave oven repair.

I seriously doubt I'll be writing a lot on this as all I'm
trying to do is make a good decision as to how to proceed.

On Mon, 17 Dec 2012 10:47:00 -0800, mike wrote:

I've fixed a few microwaves, and almost all had bad diodes.
Be aware that the big cap can hold enough charge to kill you

I don't see any diodes yet; but I do see the big cap you speak of:
http://www5.picturepush.com/photo/a/...g/11712053.jpg

On Mon, 17 Dec 2012 09:28:41 -1000, John Keiser wrote:

More irksome is a dead control panel.

I'm wiggling everything on that control panel as we speak:
http://www1.picturepush.com/photo/a/...g/11712239.jpg

On Mon, 17 Dec 2012 09:23:04 -0800, wrote:

Maybe you should buy a countertop one and look for a great
deal on a new double oven.....

I had never thought of that; thanks for the good idea.

Looks like the bottom oven is a 27 inch variety.

On Mon, 17 Dec 2012 12:20:18 -0800, mike wrote:

Inverter should let you have continuous power control.

I'm confused why an inverter is needed for an AC appliance.

I do see three voltage transformers though.
http://www4.picturepush.com/photo/a/...g/11712047.jpg

On Mon, 17 Dec 2012 12:07:35 -0600, gonjah wrote:

If you do replace it, I'm pretty sure you can find a replacement trim
for your opening. That way you don't have to worry about the exact size.

Good to know!
I'll bring the trim with me when I buy the replacement.

BTW, here's a full-size schematic where I'm looking for the
thermal switch and fuses.
http://www3.picturepush.com/photo/a/...g/11712316.jpg

"Danny D." wrote in message
...
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g., JMC1116AB)?

I have repaired a number of microwaves that I have owned. First is check the
fuse, I have had a number go for no reason. Replace it and you are good
again until it blows again in a few years. Second check the micro switches
on the door latches, they interlock for safety, if one fails the oven will
not work. There sometimes are three of them, some normally open and some
normally closed, check them with a meter.
Beyond that I have had one that burnt out a thin wire that carried about 13
amps, and then needed another part, it was cheaper to replace it than repair
it.

I've found microwaves tend to have a high voltage diode, and a high voltage
capacitor. Both are known to go bad. I've repaired several microwave ovens,
and it's been these two parts.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Danny D." wrote in message
...
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g., JMC1116AB)?

The ones I've worked on, the diode is connected to the cap.
Your diode might be going from cap to the case of the unit.

Christopher A. Young
Learn more about diodes
www.lds.org
..

"Danny D." wrote in message
...
On Mon, 17 Dec 2012 10:47:00 -0800, mike wrote:

I've fixed a few microwaves, and almost all had bad diodes.
Be aware that the big cap can hold enough charge to kill you

I don't see any diodes yet; but I do see the big cap you speak of:
http://www5.picturepush.com/photo/a/...g/11712053.jpg

Part labelled "H.V. Diode". Next to the magnetron, about 7 o'clock from the
magnatron. Goes to case ground, like my last post suggested.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Danny D." wrote in message
...

BTW, here's a full-size schematic where I'm looking for the
thermal switch and fuses.
http://www3.picturepush.com/photo/a/...g/11712316.jpg

In this case I believe the "inverter" is basically a switch mode power
supply to do away with the heavy transformer traditionaly used in
microwaves. Think of the PSU in your computer. As another poster mentions,
this does allow for finer power control but I never need that degree of
control in our cooking. And I've read complaints of invert failures. For
me, simple is better.


"Danny D." wrote in message
...
On Mon, 17 Dec 2012 12:20:18 -0800, mike wrote:

Inverter should let you have continuous power control.

I'm confused why an inverter is needed for an AC appliance.

I do see three voltage transformers though.
http://www4.picturepush.com/photo/a/...g/11712047.jpg

"Danny D." wrote:
On Mon, 17 Dec 2012 12:20:18 -0800, mike wrote:

Inverter should let you have continuous power control.

I'm confused why an inverter is needed for an AC appliance.

I do see three voltage transformers though.
http://www4.picturepush.com/photo/a/...g/11712047.jpg

An inverter is a switched SWITCHED POWER SUPPLY.
More efficiency less weight, no big expensive power transformer.
A magnetron has to be run full power. You just turn it on an off as needed.

In troubleshooting my brothers microwave, I forgot the exact steps we took.
Ended up wasting money before finding out transformer was bad.

Greg

Danny D. wrote:
This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no
troubleshooting for when it doesn't heat. They said the magnetron may
need to be replaced: Jenn-Air 800-536-6247 Customer Care


"When it doesn't heat..." Do you mean the microwave does everything else
EXCEPT heat the contents? That is does if LOOK like it's working, turntable
goes round, light comes on, timer works? If so, replacing the magnetron is a
good first guess.

I say this because the other stuff is governed by a printed circuit board
that has three to ten dodgy electrolytic capacitors on it. Replacing these
capacitors is pretty easy and pretty cheap.

On Mon, 17 Dec 2012 18:07:35 -0500, Stormin Mormon wrote:

The ones I've worked on, the diode is connected to the cap.
Your diode might be going from cap to the case of the unit

Ah, there was something there.
http://www5.picturepush.com/photo/a/...g/11714203.jpg

But it looks more like a rectangular ceramic resistor than a tubular
diode.

I haven't measured it due to the warnings about the charge on the
capacitor.

Today I looked at Lowes but they didn't have any black 22 inch by 13 inch
microwaves. The size seems to be the biggest hurdle.

On Mon, 17 Dec 2012 19:22:18 -0600, HeyBub wrote:

"When it doesn't heat..." Do you mean the microwave does everything else
EXCEPT heat the contents?

Yes. EVERYTHING, fan, lights, table, controls, etc. ... everything else
is working. The only thing that is not working is nothing gets heated.

On Dec 17, 9:14*pm, "Danny D." wrote:
On Mon, 17 Dec 2012 19:22:18 -0600, HeyBub wrote:
"When it doesn't heat..." Do you mean the microwave does everything else
EXCEPT heat the contents?

Yes. EVERYTHING, fan, lights, table, controls, etc. ... everything else
is working. The only thing that is not working is nothing gets heated.

Could be the magnetron, altho the usual failure is a gradual decrease
in power output so thing take longer and longer to get hot. If you
can locate the two wires going to the magnetron filament, you should
see someting less than 100 ohms for the filament. But, you have to
disconnect one wire from the filament to the power transformer before
you check the filament or you will just see the resistance of the
transformer and not the filament of the magnetron.

On Mon, 17 Dec 2012 17:04:25 +0000 (UTC), "Danny D."
wrote:

This Jenn-Air (model M170B) 1,350 Watt microwave just stopped heating:
http://www2.picturepush.com/photo/a/...g/11709330.jpg

I called Jenn-Air customer support who said there's no troubleshooting for
when it doesn't heat. They said the magnetron may need to be replaced:
Jenn-Air 800-536-6247 Customer Care

A replacement microwave oven has to fit over the electric oven:
http://www5.picturepush.com/photo/a/...g/11709333.jpg

Interestingly, (since it was above the oven) the back sticker says:
"May be built into a cabinet structure, but not for use adjacent
to (with 2 feet of) any gas or electric range, cooktop or oven."
http://www4.picturepush.com/photo/a/...g/11709332.jpg

But, that sticker also says:
This microwave is approved for mounting directly over Jenn-Air
wall ovens as follows:
W2700 Series Using MK271 Trim Kit, W3000 Series Using MK301 Trim Kit

Having never worked on a microwave, I ask what the conventional wisdom is.
Q: Is it generally feasible to replace just the magnetron?
Q: Will similarly sized microwave ovens fit (22" widex13"tallx15" deep)?
Q: Is it generally best to stick within the same brand? (e.g., JMC1116AB)?


When my JC Penny unit quit working, it turned out to be the
fuse & fuse block--badly corroded. Replaced both 5 years
ago, and they're still going strong.

--
croy

On 12/17/2012 9:06 PM, Danny D. wrote:
On Mon, 17 Dec 2012 18:07:35 -0500, Stormin Mormon wrote:

The ones I've worked on, the diode is connected to the cap.
Your diode might be going from cap to the case of the unit

Ah, there was something there.
http://www5.picturepush.com/photo/a/...g/11714203.jpg

But it looks more like a rectangular ceramic resistor than a tubular
diode.

I haven't measured it due to the warnings about the charge on the
capacitor.

Today I looked at Lowes but they didn't have any black 22 inch by 13 inch
microwaves. The size seems to be the biggest hurdle.


That's the diode I saw in the pictures and the diagram. Diodes come in
all shapes and sizes. ^_^

TDD

On Mon, 17 Dec 2012 22:08:35 -0600, The Daring Dufas wrote:

That's the diode I saw in the pictures and the diagram.
Diodes come in all shapes and sizes. ^_^

Ah. Thanks. I'll figure out how to discharge the capacitor first.
It has been sitting all day, so maybe by tomorrow it will have discharged.
My Fluke DMM has a diode test mode, so I can at least run that baseline.

On Mon, 17 Dec 2012 19:45:33 -0800, hr(bob) wrote:

If you can locate the two wires going to the magnetron filament,
you should see someting less than 100 ohms for the filament.

I was wondering WHERE the magnetron lay.

If these are the magnetron leads, they read 0.4 ohms with the Fluke in
ohms mode:
http://www2.picturepush.com/photo/a/...g/11714385.jpg

And, the diode reads OL in both directions, both forward biased and
reverse biased with the Fluke 75 in the diode mode:
http://www3.picturepush.com/photo/a/...g/11714386.jpg

On 12/17/2012 10:34 PM, Danny D. wrote:
On Mon, 17 Dec 2012 22:08:35 -0600, The Daring Dufas wrote:

That's the diode I saw in the pictures and the diagram.
Diodes come in all shapes and sizes. ^_^

Ah. Thanks. I'll figure out how to discharge the capacitor first.
It has been sitting all day, so maybe by tomorrow it will have discharged.
My Fluke DMM has a diode test mode, so I can at least run that baseline.


The safest way is to use a 100k ohm resistor across the capacitor then
check for residual voltage with your DVM. There is always The Jesus
Method for discharging caps. ^_^

TDD

"Danny D." wrote in message
...
On Mon, 17 Dec 2012 19:45:33 -0800, hr(bob) wrote:

If you can locate the two wires going to the magnetron filament,
you should see someting less than 100 ohms for the filament.

I was wondering WHERE the magnetron lay.

If these are the magnetron leads, they read 0.4 ohms with the Fluke in
ohms mode:
http://www2.picturepush.com/photo/a/...g/11714385.jpg

And, the diode reads OL in both directions, both forward biased and
reverse biased with the Fluke 75 in the diode mode:
http://www3.picturepush.com/photo/a/...g/11714386.jpg


If you are only on the filiment of the megatron and not in the circuit it is
probably ok. If the megatron is still connected, you may be meauring the
filiment windings of the transformer.

Some high voltage diodes are made of several lower voltage units in series
in the same case. The diode function of the Fluke may not have enough
voltage to check this out and will show open. Here is one way to check to
see if it is actually open.
http://www.flickr.com/photos/zenzoidman/4724416181/

They use a 9 volt battery and the voltage scale of the meter, One way will
show open and the other will show a few volts less than 9 if the diode is
good.

In article ,
"Danny D." wrote:

On Mon, 17 Dec 2012 12:07:35 -0600, gonjah wrote:

If you do replace it, I'm pretty sure you can find a replacement trim
for your opening. That way you don't have to worry about the exact size.

Good to know!
I'll bring the trim with me when I buy the replacement.

BTW, here's a full-size schematic where I'm looking for the
thermal switch and fuses.
http://www3.picturepush.com/photo/a/...g/11712316.jpg

That looks more like a "block diagram" than a schematic. If you didn't
find a folded up paper schematic tucked inside somewhere, then go online
and find one. I've read other responses, but I'm sticking with a faulty
thermal cutoff as most likely culprit.

On 12/17/2012 11:35 PM, Ralph Mowery wrote:
"Danny D." wrote in message
...
On Mon, 17 Dec 2012 19:45:33 -0800, hr(bob) wrote:

If you can locate the two wires going to the magnetron filament,
you should see someting less than 100 ohms for the filament.

I was wondering WHERE the magnetron lay.

If these are the magnetron leads, they read 0.4 ohms with the Fluke in
ohms mode:
http://www2.picturepush.com/photo/a/...g/11714385.jpg

And, the diode reads OL in both directions, both forward biased and
reverse biased with the Fluke 75 in the diode mode:
http://www3.picturepush.com/photo/a/...g/11714386.jpg


If you are only on the filiment of the megatron and not in the circuit it is
probably ok. If the megatron is still connected, you may be meauring the
filiment windings of the transformer.

Some high voltage diodes are made of several lower voltage units in series
in the same case. The diode function of the Fluke may not have enough
voltage to check this out and will show open. Here is one way to check to
see if it is actually open.
http://www.flickr.com/photos/zenzoidman/4724416181/

They use a 9 volt battery and the voltage scale of the meter, One way will
show open and the other will show a few volts less than 9 if the diode is
good.



Um, isn't "Megatron" one of the living robot Transformer creatures? ^_^

TDD

On Tue, 18 Dec 2012 00:35:25 -0500, Ralph Mowery wrote:

Here is one way to check to see if it is actually open.
http://www.flickr.com/photos/zenzoidman/4724416181/

That's a nice procedure which I will try in the morning.
Thanks for pointing it out - as I would have thought the
basic diode function of the Fluke 75 would have sufficed.

At the moment, it shows the diode as bad - but - as you
noted - that may be an anomaly due to the voltage of the Fluke
in diode mode.

From your wiring diagram that you posted earlier, the square black thing is
more likely a high voltage diode. If that goes out, the microwave hums, but
doesn't heat. If the diode goes, I'd expect the cap to lose its charge. You
might have to slice off the heat shrink to reveal the diode markings on it.
Dash, triangle, bar, dash. Somewhat like --||-- more or less.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Danny D." wrote in message
...
On Mon, 17 Dec 2012 18:07:35 -0500, Stormin Mormon wrote:

The ones I've worked on, the diode is connected to the cap.
Your diode might be going from cap to the case of the unit

Ah, there was something there.
http://www5.picturepush.com/photo/a/...g/11714203.jpg

But it looks more like a rectangular ceramic resistor than a tubular
diode.

I haven't measured it due to the warnings about the charge on the
capacitor.

Today I looked at Lowes but they didn't have any black 22 inch by 13 inch
microwaves. The size seems to be the biggest hurdle.

And, all have personal self worth, and self esteem. Until they
go bad. And then they go to a local school and spray every
one with electrons. Using a high power transformer and......

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"The Daring Dufas"
wrote in message ...


Ah, there was something there.
http://www5.picturepush.com/photo/a/...g/11714203.jpg


That's the diode I saw in the pictures and the diagram. Diodes come in
all shapes and sizes. ^_^

TDD

Should be infinite ohms one way, and then reverse the leads, and get some
where between 2k (about that) ohms the other way. My SWAG at the moment is
the diode went. If the diode shorted, the cap may be discharged now.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Danny D." wrote in message
...
On Mon, 17 Dec 2012 22:08:35 -0600, The Daring Dufas wrote:

That's the diode I saw in the pictures and the diagram.
Diodes come in all shapes and sizes. ^_^

Ah. Thanks. I'll figure out how to discharge the capacitor first.
It has been sitting all day, so maybe by tomorrow it will have discharged.
My Fluke DMM has a diode test mode, so I can at least run that baseline.

pants and wags tail Cookie! Cookie!
http://morethanaminute.com/wp-conten...ie_Monster.jpg

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"The Daring Dufas" wrote in message
...

Ah. Thanks. I'll figure out how to discharge the capacitor first.


The safest way is to use a 100k ohm resistor across the capacitor then
check for residual voltage with your DVM. There is always The Jesus
Method for discharging caps. ^_^

TDD

On Dec 18, 12:51*am, Smitty Two wrote:
In article ,
*"Danny D." wrote:

On Mon, 17 Dec 2012 12:07:35 -0600, gonjah wrote:

If you do replace it, I'm pretty sure you can find a replacement trim
for your opening. That way you don't have to worry about the exact size.

Good to know!
I'll bring the trim with me when I buy the replacement.

BTW, here's a full-size schematic where I'm looking for the
thermal switch and fuses.
*http://www3.picturepush.com/photo/a/...g/11712316.jpg

That looks more like a "block diagram" than a schematic.

Why do you say that? It sure looks like a schematic
to me. It shows the various components and the circuit
connections between them.




If you didn't
find a folded up paper schematic tucked inside somewhere, then go online
and find one. I've read other responses, but I'm sticking with a faulty
thermal cutoff as most likely culprit.

In article
,
" wrote:

On Dec 18, 12:51*am, Smitty Two wrote:
In article ,
*"Danny D." wrote:

On Mon, 17 Dec 2012 12:07:35 -0600, gonjah wrote:

If you do replace it, I'm pretty sure you can find a replacement trim
for your opening. That way you don't have to worry about the exact size.

Good to know!
I'll bring the trim with me when I buy the replacement.

BTW, here's a full-size schematic where I'm looking for the
thermal switch and fuses.
*http://www3.picturepush.com/photo/a/...g/11712316.jpg

That looks more like a "block diagram" than a schematic.

Why do you say that? It sure looks like a schematic
to me. It shows the various components and the circuit
connections between them.


Seems a little light on detail.