Microwaves & Ali transformers

I'm finding microwaves with Ali wire transformers more often now.
They are always the 'combo' or modern 'stainless steel look' ones.

Since the transformer used to give the majority of the copper, whats left is the magnetron & the little stirrer motor & maybe a small 25~50gm board transformer & a 1/2 handfull of plastic coated wire.

So a few days ago I found a nice new clean one & took it home, plugged it in & got it going with a glass of water inside it.
The water didn't get warm, so with everything else working I guessed it was something to do with the magnetron or the big transformer.

I pulled the casing off, it had security screws on it, which also stopped me from pulling it apart when I found it.
Theres a large cased fuse in microwaves, its joined to the large transformer, so I pulled it out & checked it.
It was blown.
I replaced it with one found on another microwave, tried it out.

It WORKED!!

Now I know what to do with the newer, probably Ali transformer microwaves.
FIX them!

In the library there is a microwave repair book, pretty much covers everything.
,
The main component failer seems to be operator induced.
When using the microwave & the user opens the door without actually pushing 'Stop', theres a large current going thru the safety door switches.
That causes them to weld shut & then that triggers the main fuse to blow.
After figuring this out, the repairer checks the switches, little cheap generic switches, finds one fused together, locked closed.
Then they replace all of the switches. And the fuse.

(Since whats happened to one, has happened to all of them, its just that only one has welded itself together so far, replacing only one guarantees that a different one will weld shut pretty soon afterwards.)

Ok, in theory & in practice, you need a certified electrician to OK the microwave oven before it gets used again.
(hell, you don't want to be answering questions from a insurance company...)



But now, I have a going microwave, I celebrated by microwaving microwave popcorn.

From now I'm checking any Ali wired microwaves before wrecking.
Copper winding = NZ$7
Ali winding = NZ$0.35cents
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Wanna get in good with your scrapmetal buyer?

Put a Copper coloured Ali transformer winding on top of your Ali pile.
When they pick it up....
Jump up & shout "Nah nah, thats aluminum wire, have a look, I will show you"

Scrape a bit of the varnish off & show them the silver coloured wire
& also point out the weight difference...

180 grams vs 454 grams.

I think they think the sun shines outta my rrr's now.