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Mike

On 2/13/2019 2:20 PM, wrote:
On Wed, 13 Feb 2019 13:43:17 -0800 (PST), wrote:

On Wednesday, 13 February 2019 20:07:20 UTC, wrote:
On Tue, 12 Feb 2019 15:05:11 -0800 (PST), wrote:

Well, you didn't mention WHAT country so...

I can tell you this. There are only a few types of magnetrons used in uWave ovens. If the mounting fits, 80%+ chance it works. The actual power is determined by the value of the cap and somewhat by the secondary of the transformer.

They can use a higher rated magnetron in a lower powered oven and they still save money by buying more of the same part. They save money on the transformer or the cap.

The mount has to REALLY match. Close is not good enough.
So the reason microwave ovens cycle on and off at the lower power
settings is because different caps would be needed for different power
outputs? I always thought it was the tube itself, that it worked best
at some certain power output.
Eric

Early 2 power level nukes used a capacitor & HV switch to reduce anode i. It's cheaper & more reliable to switch the power on & off. And safer. The only time it matters is with mousse.

Try cooking an egg to dispel that thought.
Older microwaves had minimum on-time because of the filament warm up
time...and the lack of high voltage power supply electronics back then.
A 10-second on-time is plenty of time for localized heating to cause
food to explode.
The newer inverter microwaves have much shorter on-times so food doesn't
explode as easily even at the same average power.

NT
Darn it! I was gonna try to make some mousse tonight in the microwave.
Eric

Under what conditions did the microwave fail?

Did it quit while in use? Between uses?
Any power outages or lightning storms in between?

I've never fixed a newer microwave. All my repairs were diode
replacements in older machines. I don't think I'd even try
to fix my Panasonic inverter without a full set of schematics.
Even then, all the sensors would be a nightmare to reverse-engineer.

I'm gonna make some guesses.
I doubt that the magnetron has failed.
Sure, it can crack if you overheatd it by running it
for long periods nearly empty.

More likely something else failed.
There's not much to cause instant failure of a magnetron
if you didn't overheat it.
I doubt that there are any high voltage components on
the controller that was replaced.
The oven is full of sensors for safety and cook control.
Any of them can cause the system to inhibit the microwave function.
I'd guess that the only things a controller would monitor
might be power supply voltage and temperature.
Just not worth the expense to do more. But there's plenty
more to go wrong.

Here's some reading material.

https://www.thermex-thermatron.com/w...netrons_v3.pdf

https://www.repairfaq.org/sam/micfaq.htm