Comments on: A Failed Bidirectional Diode In A Microwave Oven

By: LAURO FERREIRA

LAURO FERREIRA — Tue, 20 Jan 2026 14:47:25 +0000

Hi Henrique, congrats for this very well written article. I am now trying to repair a microwave oven very similar, model BMT45BRHNA, also made by Brastemp. The Magnetron (Galanz M24FB-610A) seems to be the problem, and it also made the double diode (HV-6A2PI) to burn. Your article helped me understand better how the High Voltage circuit works, and the role of the double diode. Do you know how to test a good double diode in a safe way, I mean without a HV source? Regards, Lauro Ferreira / Retired Telecom and Electronic Engineer from PUC-MG

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By: preecha narksuwan

preecha narksuwan — Thu, 16 Nov 2023 05:39:42 +0000

Such a well written article Mr. Henrique. I was searching for bidirectional diode and came across this site. I've customer with same issue. The unit also has "open" on secondary of the HV transformer and blown 15A line fuse, along with "open" bi-direction diode. Is it a good assumption that magnetron might be bad as well? Or just a bad transformer. I told customer to buy a new unit I just hope it's the right opinion. Thank you.

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 16:25:30 +0000

In reply to Lynn Blakely.

Thanks, Lynn.

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 16:24:32 +0000

In reply to Yogesh Panchal.

I agree, Yogesh. It would be another (and simplified form) of implementing it. I did in this way because I had all those components at hand with no intended use.

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 16:20:23 +0000

In reply to Carlos Bielli.

Of course, Carlos. The chimarrão is based on a plant, called herb mate (erva mate in Portughese, Yerba mate in Spanhich). Its an ancient indigenous culture. Consumed in several parts of South Brasil, Paraguay, Argentina and Uruguay. Thanks

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 16:14:18 +0000

In reply to Gift Elijah.

Thanks, Gifts.

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 16:12:45 +0000

In reply to Menahem Yachad.

Thanks, Menachem. As a mattter of fact the picture shows my computer workplace. I am relutant in showing my electronic lab because of some disorder.

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 16:08:47 +0000

In reply to Graeme.

It simplifies the future maintenance works. Thanks.

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 16:07:37 +0000

In reply to Albert van Bemmelen.

The AC adapter and the LED were installed out of the radiation chamber. No problems with that.

Amazing your Samsung oven working for nearly 30 Years without maintenance. The added power cord with the switch is a good idea, but you must readjust the clock at each power-on.

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By: Henrique J. G. Ulbrich

Henrique J. G. Ulbrich — Mon, 10 Oct 2022 15:59:55 +0000

In reply to Parasuraman S.

Thanks, Parasuraman. I always try to write in such a way that all can understand and enjoy.

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