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Dometic microwave no START

joebedford
Nomad II
Nomad II
My Dometic microwave will not start. All the other buttons work. Interweb scanning I've done points to a faulty control board. (or door switches but they look good).

I can find similar / identical(?) boards for other brands, but nothing for Dometic.

Can you recommend a source?

Also, any other ideas what the problem is?
21 REPLIES 21

Bobbo
Explorer II
Explorer II
joebedford wrote:
OP here:

Well, it's fixed. I finally got around to checking the 3 door switches, but unfortunately (I thought) they were all good. However I noticed the assembly that holds the switches didn't look quite right. The first photo was the assembly as it was when I opened the microwave and the second was with the tab hooked over the notch in the frame. That change moved the top switch 1mm, but IT WORKS! YAY.

It must have been a helluva bump going down the road to shift that tab (yes, we hit some pretty wicked ones) or it was installed that way in the factory in China and the plastic finally bent enough to move the assembly.

I never did find the main fuse, but I'm pretty sure it's good. 🙂

Apparently, your photo hosting site won't let anyone who is not logged into your account see the photos.
Bobbo and Lin
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joebedford
Nomad II
Nomad II
OP here:

Well, it's fixed. I finally got around to checking the 3 door switches, but unfortunately (I thought) they were all good. However I noticed the assembly that holds the switches didn't look quite right. The first photo was the assembly as it was when I opened the microwave and the second was with the tab hooked over the notch in the frame. That change moved the top switch 1mm, but IT WORKS! YAY.

It must have been a helluva bump going down the road to shift that tab (yes, we hit some pretty wicked ones) or it was installed that way in the factory in China and the plastic finally bent enough to move the assembly.

I never did find the main fuse, but I'm pretty sure it's good. 🙂

https://photos.app.goo.gl/qUuFosjxYADSUm166

https://photos.app.goo.gl/Qo71Dv3ji1n6Wsqd9

I don't know why the images don't show up so I put hyperlinks to them instead.

time2roll
Nomad
Nomad
joebedford wrote:
OP here: guess what? - we bought a spare microwave for $70.

Of course, today the built in OTR works! ARGHHHHHHHhhhhh
I always say if you carry a spare the original will never break or fail but this is ridiculous. 😉

enblethen
Nomad
Nomad
do a search for Microwave Control Board 6871W1A405A

Bud
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joebedford
Nomad II
Nomad II
I wish I had your skills.

The microwave started to NOT work later this afternoon.

I'm guessing that I need to replace the control board but where to find it?

MEXICOWANDERER
Explorer
Explorer
When Chinese are tasked with circuit design, standardization goes out the window. I've encountered units that devoted only part of a control circuit to a control circuit fuse. A turntable operated by a control circuit fuse. Keypad lighting with the power fuse. When I had oodles of time and electronics I remade m commercial LG circuit boards using better transistors, higher voltage capacitors using a hot air gun.
I also sealed the board using 3M sealant. The unit is alive and well a hundred feet from cashing tropical Pacific Ocean waves, nine years later.

joebedford
Nomad II
Nomad II
OP here: guess what? - we bought a spare microwave for $70.

Of course, today the built in OTR works! ARGHHHHHHHhhhhh

joebedford
Nomad II
Nomad II
MEXICOWANDERER wrote:
I would tend to take another look to find a 15 amp slo blo fuse.
Even though the microwave works in a non-useful way?

MEXICOWANDERER
Explorer
Explorer
I would tend to take another look to find a 15 amp slo blo fuse.

Joe417
Explorer
Explorer
Could it be just the key pad??
Joe and Evelyn

1995brave
Nomad
Nomad
Years ago had a microwave that did the same thing. Found it was the microswitch for the door. They used a cheap 1 amp switch that the contacts burned. Replaced it with a 5 amp unit and the microwave is still working today. So that one dollar microswitch killed an expensive microwave.

joebedford
Nomad II
Nomad II
Thanks for the suggestions.

Didn't see any fuses but I can put my meter on the door switches.

I realize Dometic / LG doesn't have the best reputation but it worked fine for 11 years. I'm not going to fool with the microwave generator - my life is worth to much (to me anyway) but that appears to be working (there's a combination of buttons that will start it in a useless way (but it works) - just not with the start button.

Incidentally, if the microwave works in this 'odd mode' I'm guessing that means the door switches are working.

Do you think the refurb LG board on ebay is compatible?

wa8yxm
Explorer III
Explorer III
pianotuna wrote:
My dometic turntable stopped. As I use it mostly for warming up things, it is not worth the effort of replacing the darn thing.


Same here.. That was the thing on my Dometic by LG that did not work
If you look you will find the triple arm does not go all the way onto the motor shaft. If you SLIGHTLY enlarge one of the holes it passes through (I think the bottom one) then it can push all the way onto the motor shaft.

Also GE uses the same exact motor but with a slightly longer metal shaft... Back on 2005/6 I posted the model number of that motor to multiple forums... And it lasted 16 years.
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StirCrazy
Navigator
Navigator
joebedford wrote:
My Dometic microwave will not start. All the other buttons work. Interweb scanning I've done points to a faulty control board. (or door switches but they look good).

I can find similar / identical(?) boards for other brands, but nothing for Dometic.

Can you recommend a source?

Also, any other ideas what the problem is?


test the door switches, even thought they look good they are one of the most comon failures in microwaves. as for he board most places cant get new ones for "rv microwaves" but they can repair them in they find the issue. when mine died it cost me 50 bucks for them to change out a plug that was cheep and failed.
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