Samsung microwave question (overheating??)

[TA7205]

Hello;

I'm working on a Samsung MN4371G microwave.

At first, the oven seemed fine, but the magnatron stayed
energized after a 2 min cook test. I had to pull the plug.

After that, it behaved normally. Cooking seemed alright too.
However, the magnatron became very hot, almost too hot to touch
(body of mag. itself) after a 5min. cook cycle.

I started testing for excessive current. I measured 2000v at rectifier.
(seems norm.)
To double check, I stuck a 10ohm10w resistor in series with the
rectifier to measure v-drop. It only measured 2v.. That's about 200ma,
about normal isn't it ?

Does this model run hot or am I missing something here ?
Thanks in advance,
Rick

[Sam Goldwasser]

How is the air flow? The magnetron needs LOTS of cooling.

If it remained energized after the cycle was over, that has nothing to
to with any magnetron problem. Could be a sticking relay or bad triac.

It WILL happen again.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
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[Arthur Jernberg]

Agreed: check for blocked air flow or a cooling fan that is inop, etc. Also
the mag should not operate once the controller shuts down the cook cycle.
Check all the safety switches, and controller for malfunctions.
Sam Goldwasser <s...@stdavids.marconimed.com> wrote in message
news:SAM.00Ma...@colossus.stdavids.marconimed.com...

[Christopher R. Smyth]

Reminds me of my old microwave. The door safety switch stuck, and i opened
it oneday to almost cook myself. 4 seconds is too much for a human to take.

The guy at the hospital called me radioactive man.

Chris

TA7205 <ta7...@aol.com> wrote in message
news:20000503151952...@ng-cs1.aol.com...

[lomet...@gmail.com]

Mine does that too. I just set the fan speed to 4 so it doesn't overheat

[Adrian Caspersz]

On 16/04/17 23:33, lomet...@gmail.com wrote:
> Mine does that too. I just set the fan speed to 4 so it doesn't overheat
>

Responding to a 17yr old post.



Nothing to see here, move along ....

--
Adrian C

[pf...@aol.com]

Other than the fact that when a microwave oven starts to act out in this manner, the only safe 'next stop' is the knacker's yard.

Peter Wieck
Melrose Park, PA

[tabb...@gmail.com]

On Monday, 17 April 2017 21:49:08 UTC+1, pf...@aol.com wrote:
> On Monday, April 17, 2017 at 4:34:47 AM UTC-4, Adrian Caspersz wrote:
> > On 16/04/17 23:33, lomet...@gmail.com wrote:
> > > Mine does that too. I just set the fan speed to 4 so it doesn't overheat
> > >
> >
> > Responding to a 17yr old post.
> >
> >
> >
> > Nothing to see here, move along ....

> Other than the fact that when a microwave oven starts to act out in this manner, the only safe 'next stop' is the knacker's yard.
>
> Peter Wieck
> Melrose Park, PA

It's many years since I saw a microwave capable of cooking with the door opened. Any such machine should be got rid of even if working ok, because one day it won't be. Since teh early 80s all machines (here at least) have had an interlock system that can't fail unsafely. Well almost, unfortunately. Always check the shorting resistor if there's any question at all of the interlock system's reliability.


NT