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Home > Archive > Electrical Engineering > July 2007 > Microwave oven Diode Burnout ?
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| Author |
Microwave oven Diode Burnout ?
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| still me 2007-07-21, 1:25 pm |
| I need help from someone with an understanding of how Microwave oven's
work.
The high voltage diode in my Microwave has burned out three times now.
While the original diode lasted years, the first replacement went
about six months (OEM part) the second replacement went another six
months (direct from manufacturer). Now I am faced with replacing it a
third time.
Everything else looks and tests out in there just fine according to
the manufacturer's test grid and basic testing (like the capacitors
appearing to have the right value, etc, switches all working). It does
not die in a spectacular way, it just stops heating.
Obviously there's something else wrong here. Does anyone have
knowledge of how these things work, and why the diode might be going
bad repeatedly.
(In answer to the question "why not just buy a new one for $100" -
this is a large built in stove hood/micro, matching the stove and the
rest of the kitchen, in a color that can no longer be matched. It's
probably 8-10 years old overall).
Thanks,
| |
| Beachcomber 2007-07-21, 1:25 pm |
| Two easy things to check:
1. Is the unit getting enough cooling air? Check to see if vents are
partially or fully blocked and make sure that the required clearances
are met.
2. (Less likely) but, check the incoming line voltage. If you live
in North America, it should be 120V plus or minus 5%.
When I bought my house, the builder offered a built-in unit. I
declined for reasons similar to those you mentioned. Too much
customization and hassle when the unit goes bad. Even though I gave
up counter space for a free-standing unit, when the last microwave I
owned went bad, I replaced it for a new unit, on sale for $60.
Microwave ovens are almost a commodity item these days.
>I need help from someone with an understanding of how Microwave oven's
>work.
>
>The high voltage diode in my Microwave has burned out three times now.
>While the original diode lasted years, the first replacement went
>about six months (OEM part) the second replacement went another six
>months (direct from manufacturer). Now I am faced with replacing it a
>third time.
>
>Everything else looks and tests out in there just fine according to
>the manufacturer's test grid and basic testing (like the capacitors
>appearing to have the right value, etc, switches all working). It does
>not die in a spectacular way, it just stops heating.
>
>Obviously there's something else wrong here. Does anyone have
>knowledge of how these things work, and why the diode might be going
>bad repeatedly.
>
>(In answer to the question "why not just buy a new one for $100" -
>this is a large built in stove hood/micro, matching the stove and the
>rest of the kitchen, in a color that can no longer be matched. It's
>probably 8-10 years old overall).
>
>Thanks,
>
| |
|
| In article <rf64a3tdmjcine9r3cidk8qbmq1fci7d84@4ax.com>,
wheeledBob@yahoo.com says...
> I need help from someone with an understanding of how Microwave oven's
> work.
No help here, I replace 'em.
> (In answer to the question "why not just buy a new one for $100" -
> this is a large built in stove hood/micro, matching the stove and the
> rest of the kitchen, in a color that can no longer be matched. It's
> probably 8-10 years old overall).
Our house is 20YO with the microwave built into the copper range
hood. When it went, about 5 years back, I found that it wasn't tough
to find a replacement, though it helps if you like black, white, or
stainless. ;-) While the built-ins with exhaust fans aren't cheap
(I paid about $600 with a convection-oven that's never been used),
they are available and seem to be a standard size. One may have to
do some "invention" to install the new one though.
--
Keith
| |
| joe.blow 2007-07-22, 3:25 am |
| The most common microwave failures are the Fuse and or the fuse holder. If you have a diode
that keep failing then it must be either to much current or voltage going to it.
Check all connectors and replace any that are over heated and discolored. I have found most
of the time that the fuse holder even though it looks fine starts failing and you get a high voltage
drop across it and that raise the current in everything else to give the same watts with less voltage.
| |
| Spurious Response 2007-07-22, 3:25 am |
| On Sat, 21 Jul 2007 14:45:28 GMT, still me <wheeledBob@yahoo.com> wrote:
>I need help from someone with an understanding of how Microwave oven's
>work.
>
>The high voltage diode in my Microwave has burned out three times now.
>While the original diode lasted years, the first replacement went
>about six months (OEM part) the second replacement went another six
>months (direct from manufacturer). Now I am faced with replacing it a
>third time.
>
>Everything else looks and tests out in there just fine according to
>the manufacturer's test grid and basic testing (like the capacitors
>appearing to have the right value, etc, switches all working). It does
>not die in a spectacular way, it just stops heating.
>
>Obviously there's something else wrong here. Does anyone have
>knowledge of how these things work, and why the diode might be going
>bad repeatedly.
>
>(In answer to the question "why not just buy a new one for $100" -
>this is a large built in stove hood/micro, matching the stove and the
>rest of the kitchen, in a color that can no longer be matched. It's
>probably 8-10 years old overall).
>
>Thanks,
Find a suitable replacement that incorporates a heatsink in the
package. That should extend its life beyond that of the original or OEM
replacements.
Their "OEM" replacement *may* be a device that they call for on many
models, but may not have been the same device that was originally
installed in your unit.
| |
| Spurious Response 2007-07-22, 3:25 am |
| On Sat, 21 Jul 2007 14:38:36 -0400, krw <krw@att.bizzzz> wrote:
>No help here, I replace 'em.
Right. Like you have "worked on" numerous MW ovens.
| |
| Spurious Response 2007-07-22, 3:25 am |
| On 22 Jul 2007 02:31:54 GMT, joe.blow <joe.blow@yahoo> wrote:
>The most common microwave failures are the Fuse and or the fuse holder. If you have a diode
>that keep failing then it must be either to much current or voltage going to it.
You're an idiot, and you put shame on your stolen nym, XXXXXXX. Joe
Bloe knows far more than you do.
>
>Check all connectors and replace any that are over heated and discolored. I have found most
> of the time that the fuse holder even though it looks fine starts failing and you get a high voltage
>drop across it and that raise the current in everything else to give the same watts with less voltage.
Total mental retardation.
| |
| Rheilly Phoull 2007-07-22, 9:25 am |
|
"still me" <wheeledBob@yahoo.com> wrote in message
news:rf64a3tdmjcine9r3cidk8qbmq1fci7d84@4ax.com...
>I need help from someone with an understanding of how Microwave oven's
> work.
>
> The high voltage diode in my Microwave has burned out three times now.
> While the original diode lasted years, the first replacement went
> about six months (OEM part) the second replacement went another six
> months (direct from manufacturer). Now I am faced with replacing it a
> third time.
>
> Everything else looks and tests out in there just fine according to
> the manufacturer's test grid and basic testing (like the capacitors
> appearing to have the right value, etc, switches all working). It does
> not die in a spectacular way, it just stops heating.
>
> Obviously there's something else wrong here. Does anyone have
> knowledge of how these things work, and why the diode might be going
> bad repeatedly.
>
> (In answer to the question "why not just buy a new one for $100" -
> this is a large built in stove hood/micro, matching the stove and the
> rest of the kitchen, in a color that can no longer be matched. It's
> probably 8-10 years old overall).
>
> Thanks,
>
Why not get one from a higher rated unit and give that a try ? (The previous
suggesting regarding ventilation is very valid too!)
--
Cheers .......... Rheilly P
| |
|
| In article <fs46a39ui7erdaqdiv8lsqs2dosdljf3b8@4ax.com>,
SpuriousResponse@cleansignal.org says...
> On Sat, 21 Jul 2007 14:38:36 -0400, krw <krw@att.bizzzz> wrote:
>
>
>
> Right. Like you have "worked on" numerous MW ovens.
Exactly my point, Dimbulb.
--
Keith
| |
|
| In article <uu46a31n7fh4p8s81i212ast1bbgkit31i@4ax.com>,
SpuriousResponse@cleansignal.org says...
> On 22 Jul 2007 02:31:54 GMT, joe.blow <joe.blow@yahoo> wrote:
>
>
> You're an idiot, and you put shame on your stolen nym, XXXXXXX. Joe
> Bloe knows far more than you do.
>
> Total mental retardation.
Your usual "contribution" to the Usenet community, Dimbulb?
--
Keith
| |
|
|
> When I bought my house, the builder offered a built-in unit. I
> declined for reasons similar to those you mentioned. Too much
> customization and hassle when the unit goes bad. Even though I gave
> up counter space for a free-standing unit, when the last microwave I
> owned went bad, I replaced it for a new unit, on sale for $60.
> Microwave ovens are almost a commodity item these days.
1) If you aren't particular about colour, you can replace them for about
$120/US. You can get a "pretty good" model for less than $200. Remember
that the uWave also replaces the over the stove fan unit including the
light. They have extra thermostats inside to shut things off before
anything gets too hot. They will also automatically turn on the fan if the
over gets things too hot. I don't know about the "builder's models" but
the one comsumers buy are of a good quality.
2) My firs uWave lasted over 25 years. It was a good quality unit for
the time with extra features (for the time).
3) Just so you know, an over the oven uWave is partly supported by the
cabinet that's on top of it and partly by a stamped steel plate which is
attached to something strong in the wall. The power comes from an outlet
wired into the cabinet and the cord runs through a hole you make in the
cabinet. The unit I installed in my rental is about 6 years old. The one
in my home is about 1 year old.[color=darkred]
>
>
My old one that lasted 25 years had a voltage doubler and transformer for
the magnitron supply. I would think one would replace the diode and the
doubling cap at the same time.
Frankly, I agree with others than when it gives trouble you replace it.
That's what I would do even with the somewhat fancy model ($270) my wife got
me to put in.
There are FOUR basic "colors" and one should suit you. They are: White,
Black, Stainless Steel, and some variation of "Yellow." The latest version
of "yellow" is an "off white". Black or Stainless goes with anything. If
you have very old appliances, the current "yellow" may not work for you.
| |
| Spurious Response 2007-07-22, 8:25 pm |
| On Sun, 22 Jul 2007 08:57:28 -0400, krw <krw@att.bizzzz> wrote:
>In article <fs46a39ui7erdaqdiv8lsqs2dosdljf3b8@4ax.com>,
>SpuriousResponse@cleansignal.org says...
>
>Exactly my point, Dimbulb.
Aren't you the fucking retard that still contends that the PS3 is not a
nine core IBM Cell Processor array?
Bet you deny that it runs Linux too, eh?
| |
| Martin Crossley 2007-07-22, 8:25 pm |
| nni/gilmer@nni.com wrote:
>
> 1) If you aren't particular about colour, you can replace them for
> about $120/US. You can get a "pretty good" model for less than
> $200. Remember that the uWave also replaces the over the stove fan
> unit including the light. They have extra thermostats inside to
> shut things off before anything gets too hot. They will also
> automatically turn on the fan if the over gets things too hot. I
> don't know about the "builder's models" but the one comsumers buy are
> of a good quality.
>
> 2) My firs uWave lasted over 25 years. It was a good quality unit
> for the time with extra features (for the time).
>
> 3) Just so you know, an over the oven uWave is partly supported by
> the cabinet that's on top of it and partly by a stamped steel plate
> which is attached to something strong in the wall. The power comes
> from an outlet wired into the cabinet and the cord runs through a
> hole you make in the cabinet. The unit I installed in my rental is
> about 6 years old. The one in my home is about 1 year old.
>
> My old one that lasted 25 years had a voltage doubler and transformer
> for the magnitron supply. I would think one would replace the diode
> and the doubling cap at the same time.
>
> Frankly, I agree with others than when it gives trouble you replace
> it. That's what I would do even with the somewhat fancy model ($270)
> my wife got me to put in.
I'm sorry that I can't agree about replacing the whole unit.
For that amount of money, surely it must be more economical and rewarding to
repair the old one and avoid unnecessary waste/ landfill, as long as it's
not rusty inside and the hinges aren't worn.
I do agree about replacing the diode & capacitor as a pair next time,
though. Still not expensive.
If it still fails, then perhaps even the magnetron as well, the time after.
Or even pay good money and take it to a workshop which will offer a
guarantee on the work!
Still cheaper than a complete equivalent replacement oven.
>
> There are FOUR basic "colors" and one should suit you. They are:
> White, Black, Stainless Steel, and some variation of "Yellow." The
> latest version of "yellow" is an "off white". Black or Stainless
> goes with anything. If you have very old appliances, the current
> "yellow" may not work for you.
| |
|
| In article <aur7a3970p65ghfvo077uncrpd7h381jdb@4ax.com>,
SpuriousResponse@cleansignal.org says...
> On Sun, 22 Jul 2007 08:57:28 -0400, krw <krw@att.bizzzz> wrote:
>
>
>
> Aren't you the fucking retard that still contends that the PS3 is not a
> nine core IBM Cell Processor array?
Clueless, as always, Dimbulb.
> Bet you deny that it runs Linux too, eh?
Even I can't believe you're this dim, Dimmie.
--
Keith
| |
| Spurious Response 2007-07-22, 9:25 pm |
| On Mon, 23 Jul 2007 02:11:55 +0100, "Martin Crossley"
<Martin@g8uwm.NOSPAMabelgratis.net> wrote:
>If it still fails, then perhaps even the magnetron as well, the time after.
>Or even pay good money and take it to a workshop which will offer a
>guarantee on the work!
> Still cheaper than a complete equivalent replacement oven.
Actually, the replacement magnetron is very likely quite expensive, and
would be the point at which choosing a new unit is a better solution.
Would it not be better to get the schematic for it, and try to find out
why the diode is blowing?
The fix is likely a beefier diode. Inexpensive, and the right
solution.
| |
| Spurious Response 2007-07-22, 9:25 pm |
| On Sun, 22 Jul 2007 21:18:00 -0400, krw <krw@att.bizzzz> wrote:
>In article <aur7a3970p65ghfvo077uncrpd7h381jdb@4ax.com>,
>SpuriousResponse@cleansignal.org says...
>
>Clueless, as always, Dimbulb.
Tell us, oh guru of bullshit... what does the PS3 run as a CPU?
>
>
>Even I can't believe you're this dim, Dimmie.
I can't believe that you actually contend that you know what it is, yet
cannot declare it when you claim I am wrong.
Well, fucktard... what does it run?
Just so you know, idiot, it was SONY that recruited a cluster server be
made with the CELL CPU PS3s that run Linux. That was even before the
platform was ever released.
| |
|
| In article <r528a3prkh6k4gletjn4pc8pk5hof3ni05@4ax.com>,
SpuriousResponse@cleansignal.org says...
> On Sun, 22 Jul 2007 21:18:00 -0400, krw <krw@att.bizzzz> wrote:
>
>
> Tell us, oh guru of bullshit... what does the PS3 run as a CPU?
>
> I can't believe that you actually contend that you know what it is, yet
> cannot declare it when you claim I am wrong.
Are you really as stupid as you pretend Dimmie?
> Well, fucktard... what does it run?
>
> Just so you know, idiot, it was SONY that recruited a cluster server be
> made with the CELL CPU PS3s that run Linux. That was even before the
> platform was ever released.
Yes, apparently you are.
--
Keith
| |
| Spurious Response 2007-07-23, 3:25 am |
| On Sun, 22 Jul 2007 22:12:10 -0400, krw <krw@att.bizzzz> wrote:
>In article <r528a3prkh6k4gletjn4pc8pk5hof3ni05@4ax.com>,
>SpuriousResponse@cleansignal.org says...
>
>Are you really as stupid as you pretend Dimmie?
>
>
>Yes, apparently you are.
Maybe one day you will get a clue, boy.
http://en.wikipedia.org/wiki/PS3
http://en.wikipedia.org/wiki/Cell_microprocessor
Runs Linux.
Uses Cell BE processor.
Is being utilized in cluster type supercomputers.
Since all you come back with are stupid little fucktard remarks, I will
assume that you have been full of shit every time you ever remarked on
these items.
Since I already know that you have been a stupid little fucktard all
these years, I will assume that you have nothing of substance to offer.
| |
|
| In article <sl58a3l8qns4v9kq3i84q7lbjvffjcd43g@4ax.com>,
SpuriousResponse@cleansignal.org says...
> On Sun, 22 Jul 2007 22:12:10 -0400, krw <krw@att.bizzzz> wrote:
>
>
>
> Maybe one day you will get a clue, boy.
>
> http://en.wikipedia.org/wiki/PS3
>
> http://en.wikipedia.org/wiki/Cell_microprocessor
>
> Runs Linux.
>
> Uses Cell BE processor.
>
> Is being utilized in cluster type supercomputers.
You *are* stupid.
> Since all you come back with are stupid little fucktard remarks, I will
> assume that you have been full of shit every time you ever remarked on
> these items.
When brainless pond scum is talking...
> Since I already know that you have been a stupid little fucktard all
> these years, I will assume that you have nothing of substance to offer.
As always, Dimbulb, you know nothing.
--
Keith
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