• ** REMEMBER! **The microwave can still shock you even unplugged!!

    ALWAYS discharge the high-voltage capacitor first if you even think your hands will come close to any HIGH VOLTAGE components.

    Jeff mentions this: Anything in the high voltage ( magnetron, capacitor, diode, wires to and from ):
    ...Use a metal ( not the shiny chrome type ) screw driver with a insulated handle to short across ( touch both at the same time ) the terminals of the high voltage capacitor to discharge it.

    From Jeff's site: http://www.applianceaid.com/component-testing.php

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ME18H704SFS/A Samsung Microwave Can’t Pop Corn?


Premium Member
Mar 18, 2020
Winnipeg Canada
Model Number
Less than 1 year
Hi all,
Our one year old OTR Samsung microwave can not successfully pop corn. By that I mean that when we put 1/3 cup of corn kernels in a microwave popcorn bowl and use either the popcorn sensor feature or simply two minutes on high power there are approximately 60% of the kernels in-popped. If we try to extend the high power run time to four minutes run time then we still have about 50% of the kernels in-popped, the corn that does pop starts to brown in that time and the un-popped kernels look charred.
We have tried our same kernels and popcorn bowl in our daughter’s LG countertop microwave and in my sister-in-law’s Samsung OTR microwave (similar model to ours but an older version) and the corn pops perfectly and quickly (less than 2 minutes run time. So our corn and bowl are not a problem.
I have measured our household AC power supply while running the microwave and it is ok (119 VAC under load and drawing 15 amps. The circuit is a 20 amp circuit dedicated to only the microwave oven. So our AAC supply is not a problem.
We have had, under warranty, the magnetron, power transformer, high voltage capacitor and diode replaced twice with no improvement.
I have done a water heating test as per the IEC 705 method and always get around 700 watts RF output power. Samsung claims that this microwave puts out 950 watts.
Samsung tells us that the microwave is working correctly according to specification and are now refusing to do anything more for us.
I would appreciate receiving any thoughts or suggestions anyone may have. In particular what is your experience with popping corn in a Samsung microwave? Or any other brand? YouTube has lots of videos showing successful corn popping in a microwave. What can’t we do it?
Thanks in advance
Call Samsung and set up a warranty service call or return it for a replacement. Everything is covered for the first year. If you attempt a repair you risk losing your warranty. Sounds like a defective mag tube.
Rick...thanks for your reply. Unfortunately I am on the third magnetron already. I suppose that Samsung could have manufactured a bad batch of magnetrons but I think the probability of that is low. The microwave draws 15 amps when running so that indicates the magnetron is consuming power....although perhaps not converting it very well into RF power?
I have been pushing Samsung on this since November 2019 and they finally have said it is working as it should and have refused to replace it. Very confusing to me. As a last resort I will go back to the manager of the Home Depot store where we bought it and ask for a replacement.
Put one cup of water in the microwave for one minute on high. Does it boil?
Sorry, My bad. It's 8oz (250ml) room temperature water in the center of the microwave. Water will boil in 3.5 to 4 minutes. Sorry for the misinformation.
No problem. I appreciate your input.
As I mentioned in my initial post I did the IEC 705 water heating test which heats up one litre of water for 60 seconds and measures the before and after water temperatures. Doing a little math and using a conversion factor from calories to joules to watts this technique let’s you measure the actual out put watts of microwave energy. In my case my Samsung claimed 950 watt oven only puts out about 700 watts. Somethings no wrong somewhere. The magnetron is an OM75 P ESGN which seems to be a standard used in a lot of their microwaves.
Samsung claimed 950 watt oven only puts out about 700 watts.
I've never heard that before. Yours is 1000 watt and should have 1000 watts cooking power
I did the IEC 705 water heating test which heats up one litre of water for 60 seconds and measures the before and after water temperatures. Doing a little math and using a conversion factor from calories to joules to watts this technique let’s you measure the actual out put watts of microwave energy.
Yeah I get it, one watt is equal to one joule per second. Watts Law- P = V I and all that. It's way too complicated for the average Joe. If you want to know the wattage of your microwave do it my way and tell me what you get. Put the cup of water in the microwave and see how long it takes the water to boil:
1.5 minutes: 1200 watts
2 minutes: 1000 watts
2.5 minutes: 800 watts
3 minutes: 700 watts
4 minutes: 600 watts
My oven boils 1 cup of water around 2:45 minutes. Difficult to see through the mesh window but definitely boils after 2.5 minutes and before 3.0 minutes. So somewhere between 700 and 800 watts.
You say my oven is 1000 watts. It is interesting that the power rating changes with the country. My manual says that this oven is 1000 watts in the US and 950 watts in Canada. The sticker inside the door says 950 watts. Wonder why that is. Guess American volts are stronger than Canadian volts?
Good question but I don't know the answer. Makes me wonder about all these mag tubes that have been replaced and if they are the correct part. 700 watts is why your popcorn won't pop all the way. Even if it's 950 watts that's still a 200 watt difference. Having all the high side components replaced already and several mag tubes there's nothing else I can tell you that would be helpful except what I tell everyone, stay away from LG and Samsung appliances. I'll attach the spec sheet for that model. It shows 1000 watt cooking power and that's what you're not getting.


  • ME18H704SFS spec sheet.PDF
    891.7 KB · Views: 352
Thanks again Rick. Yes, one needs fast high heat for good corn popping. My oven is only capable of slow low heat consequently poor popping.
I tend to agree with your overall opinion of Samsung. In my on-line searches for help on this problem I discovered the US Govt web site FCC ID on which all manufacturers that produce radio frequency emitting devices must submit test results to prove the proper operation of their devices. Microwave ovens fall under this rule. One of the required tests is the IEC 705 water heating tests. I have noticed in the published Samsung microwave oven test results that there is some “creative” math used by Samsung to provide a result equal to 1000 watts. By contrast LG provides a clearly written and detailed test report which leaves no doubt as to the veracity of their output power claims.
If you pop a lot of popcorn your next microwave should be a minimum 1200 watts
Yes, my wife loves popcorn!
So the latest news is Samsung called me yesterday and, after telling me at the beginning of the week that they would do nothing for me, have now told me that they will replace my microwave. They will either replace mine with an identical unit if it is still available or refund my purchase. Apparently a 2-3 week process to do this. Good news as far as I am concerned.
Thanks again for your discussion on my problem.
First of all I want to say that I hope everyone doing ok with the Covid-19 situation. The last time I replied to this discussion thread it wasn’t even on the radar for most folks. How times change.

So I just wanted to let everyone know the end result on my popcorn adverse microwave. Today I just received the replacement microwave from Samsung. It is not the exact same model but very similar. My previous model is no longer available so Samsung gave me an ME19R7041FS/AC. Slightly larger oven capacity and same features and most importantly the same rated output power, 950 watts (in Canada, 1000 watts in the US).

So of course after installing it we immediately tried to pop some corn and....guess what? It did not pop the corn any better than our original microwave. It left more than 1/2 of the kernels un-popped. Tried a number of ways, sensor controlled, three minutes on high, special popping bowl, plain paper bag. Nothing worked. Always left lots of unpopped kernels.

So now we are frustrated and confused.
Sounds like Samsung doesn't make a good popcorn microwave. Did you try a different brand microwave popcorn?
Hi Shmowzow,
Thanks for your feedback. I am glad to hear that someone else has had this same problem. It is my opinion, after doing a lot of tests on my microwave ovens and also reading test results that manufacturers must publish on the US govt FCC ID database, that Samsung is playing fast and loose with their claim of a 900 watt output on these microwave ovens. If you look at the math and measured results in these FCC ID Samsung reports they do not equal 900 watts. If you read the reports provided by LG on the FCC ID database the test results and math match exactly to produce 900 watts. I find this interesting.
Hi! I had to let you know what I found out on another forum. I've had the same problem with my new 2 year old Samsung microwave. My old microwave would fully pop Orv Red bags and this new microwave will only pop a few kernels that burn. I read this forum today and tried the suggestion of boiling one cup of water which started boiling at 1.5 minutes which was 1200 Watts.

I looked around on other sites and read a page about the sensor not being able to sense the moisture of the kernels, so I tried what they suggested and was so excited that my Orv Red SmartPop 2.69 oz bag fully popped in a little over 3 minutes! I also felt stupid that I never saw the difference between the microwaves. My old microwave was a regular microwave, but this new Samsung is a combo Convection Microwave. I left the "metal pan" on the bottom over the glass turntable.

The "sensor" can't detect the kernel moisture through the metal used for convection. They said to take the metal tray out from the bottom, turn over a pyrex, glass or microwave-safe pie plate or cake dish and place the bag on top. You can also use a paper plate as last resort.

I first tried an inverted pyrex square cake dish, but the turntable wouldn't move so I switched to an inverted pyrex plate. I set the timer for 5 minutes not using the "popcorn" button, it started popping right away, stopped it when it was popping every 2-3 seconds after 3 minutes, wow fully popped!

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