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  • Microwave troubleshooting

    From [email protected]@21:1/5 to Michael Trew on Mon Aug 2 11:56:39 2021
    On Monday, July 26, 2021 at 2:59:16 PM UTC-5, Michael Trew wrote:
    On 7/26/2021 10:39 AM, [email protected] wrote:
    In case anyone wonders, I replaced the magnetron and it's functioning again. I partially disassembled the old one and there's nothing obviously wrong with it. I did not cut the tube apart however. I mainly wanted the magnets.
    Good job! Glad that the unit didn't go to the scrap yard in favor of a
    new one.

    Exactly. I hate throwing things out.

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  • From [email protected]@21:1/5 to Ralph Mowery on Mon Aug 2 11:58:22 2021
    On Monday, July 26, 2021 at 3:51:28 PM UTC-5, Ralph Mowery wrote:
    In article <sdn46g$2ne$[email protected]>, [email protected] says...

    On 7/26/2021 10:39 AM, [email protected] wrote:
    In case anyone wonders, I replaced the magnetron and it's functioning again. I partially disassembled the old one and there's nothing obviously wrong with it. I did not cut the tube apart however. I mainly wanted the magnets.

    Good job! Glad that the unit didn't go to the scrap yard in favor of a
    new one.


    Many times the replacement Megatron can be close to the cost of a new microwave. Especially those under $ 150 or so.

    Nah, this cost me just under $53USD shipped for an OEM part. As it's an over-the-range model, it's more expensive than the budget countertops.

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    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From [email protected]@21:1/5 to [email protected] on Sun Dec 25 11:42:52 2022
    On Saturday, July 17, 2021 at 3:57:08 PM UTC-5, [email protected] wrote:
    I have a microwave from the mid 2000s that failed on me. It uses basic circuitry: transformer, diode, cap, magnetron....not an inverter type or anything fancy like that. One morning it seemed to mostly work, but the output rapidly dropped over a few
    minutes. No bang, no smoke. Just stopped heating.

    Everything tests ok, the transformer, diode, cap, even the magnetron resistance measurements are "good". I know there's about 10A to the filament with indirect testing, and I know the capacitor has near 2kV on it right after running the unit and
    unplugging it. This was determined by knowing the cap has an internal bleeder and using the RC time constant to allow the voltage to drop to a safe value to measure.

    Would this be indicative of a bad magnetron? Almost everything I read about magnetron troubleshooting leads me to believe there's nothing wrong with it, but then again the rest of the circuit also seems to be functioning correctly.

    So.....magnetron seems to have failed again, not quite 1.5 years later. Microwave was running, then stopped heating. No bang, no smoke. I put my wattmeter on it, tried cooking again, saw around 1.2kW usage for a few seconds and thought it was ok, but
    then dropped to around 300W. I haven't taken it apart yet but my bet is a bad mag.

    This was a genuine OEM replacement part from a reputable supplier. So either 1. the part was defective and prone to early failure from the start or 2. something is making it fail early. But what? As I think about the other parts, the transformer, diode
    and capacitor, I can't come up with a way for those parts to cause early mag failure. Transformers don't fail in a way that causes increased output voltage (not that I've seen), and a bad diode or cap doesn't seem to be capable of destroying the mag.

    The original mag lasted 14 years and the usage has always been the same.

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  • From Peter W.@21:1/5 to [email protected] on Mon Dec 26 03:50:33 2022
    On Sunday, December 25, 2022 at 2:42:54 PM UTC-5, [email protected] wrote:
    On Saturday, July 17, 2021 at 3:57:08 PM UTC-5, [email protected] wrote:
    I have a microwave from the mid 2000s that failed on me. It uses basic circuitry: transformer, diode, cap, magnetron....not an inverter type or anything fancy like that. One morning it seemed to mostly work, but the output rapidly dropped over a few
    minutes. No bang, no smoke. Just stopped heating.

    Or, another part has failed. Such as a relay, the contacts within the relay, something else....

    Peter Wieck
    Melrose Park, PA

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