RFS12SW2A - Instructions

The repair went well...I am so glad that I read this info before buying a new microwave....it saved me lots of money. I did have a repair man come and look at it and he told me to buy a new one but it cost alot of money when it wasn't necessary. I did the repair and I was very proud of myself.
Three men watched a woman fix this and it was no problem...they were impressed also....

I looked up the #1 reason for no heat for my microwave on the site , and using my model number found that 92% of the time it was the Black Sleeve Diode. Ordered the $15 part, and installed it within 30 minutes. Most of the time was used for removing the built in microwave and removing the cover. Replaced the diode by finding it on the diagram that I printed from this site (free). Very relieved that we don't need to have our custom cabinetry re-sized to accommodate a new microwave. Thank you!

Over the stove microwave installed in top cabinet row.
1. Unplug device.
2. Two people to remove from wall/cabinet (remove two, large, top mounting screws and rotate entire microwave down and off the wall mount). Should be some wood spacers between top of device and bottom of cabinet.
3. Remove screws from sheet metal cover.
4. Remove one screw holding blowers in place and rotate out of the way, in order to gain access to 2 of 5 screws that hold the magnetron in place.
5. Unplug magnetron and remove the 5 screws.
6. Drop in new magnetron and re-assemble microwave in reverse order (steps 5-3).
7. Two people restore micro to wall/cabinet. Replace wood spacers, re-install two, large mounting screws (finger-tight). Test device. Secure the two large screws.

Removed case,
Discharged HV capacitor and removed cooling fan.
Unscrewed ground end of HV diode and unplugged from HV capacitor.
Installed new diode by reversing the order. In my case, the problem was the magnetron was bad, so I replaced it as well.

Initially we started looking to buy a replacement microwave to replace our 13+ year old built-in microwave. It was a real pain finding a replacement to fit the exact dimensions. So I thought I'd try to find an old KitchenAid microwave. However, I was pleasantly surprised when this site came up on my search. Their website allows me to input the problems and then it showed two possible parts that needed to be replaced. I emailed tech support and asked them which part I needed. They responded very quickly and said I needed to replace the magnetron. I watched a couple YouTube videos and then pulled my microwave apart. It was incredibly easy to pull the outer cover off. The magnetron had 5 screws that needed to be removed and one electrical plug. Took me maybe 10 min to complete the entire repair. It was one of the easiest repairs I've done and so thankful for this site They saved me a ton of money from not buying a new microwave and we now have our microwave working again. In hindsight, I wouldn't hesitate. I'd order the Part now and get it fixed.

removed cover first ,then I disconnected the leads and removed the holding screws that held it in place. Then I installed the new part by reversing the prosedure.

Unplug the microwave. Remove the Philips head and safety Torx head screws along the bottom of the sides and rear of the microwave which hold the black cover on. Lift the cover up at the rear and slide it backwards to disengage the tabs on the front top. Remove the cover. Discharge the capacitor by shorting the terminals to each other and then ground. Do this with a well insulated object and be aware there may be a pop when you do this. Keep hands, etc. on the insulated part of the object (screwdriver handle, etc). There's a lot of stored energy in that capacitor. I'd advise first checking the diode to make sure its not bad. Replace it if it is. The Magnatron is held in with a couple of screws on the top and sides. Unplug the connector and remove the screws. Remove the Magnatron. Installation is the reverse of removal.

I had to unmount the over-the-range microwave oven to be able to gain access to the interior of the oven. Complicating removal (and re-installation) was the fact that there is a "pot-filler" faucet installed directly underneath the oven. In retrospect, I should've removed the faucet before doing the repair, but "c'est la vie."

After I got the microwave down, removing the case was also "interesting." I get bonus points for the fact that the previous owner must've had to replace the same diode before - and then re-assembled the microwave case incorrectly - thereby adding to the confusion (BTW, the service manual that I found online said nothing about how to remove the oven's case).

To remove the case, undo all the screws holding it on, and then rotate the case upwards from the back while also pulling the case backwards. There are crimped folds on the inside of the case that mate with the back edges of the front of the oven's chassis, and these folds have to be unclipped from the chassis in order to remove the case.

Replacing the diode itself was the easiest part of the job. The two connectors on the diode are of different types, making it impossible to install the diode with the wrong polarity.

BTW, the diode that had failed was not an OEM diode; I suspect it was a generic component that had been installed by a repairman sometime between 2004-2008 (when our home's original owners still owned the home). On the other hand, the new diode from PartSelect is an OEM part (it came packaged in a sealed Whirlpool bag).

The fact that the oven had stopped heating indicated that it was either the high-voltage diode or the magnetron that had failed. Since a replacement diode costs ~ 1/10th as much as a replacement magnetron, I figured it made sense to replace the cheaper part first. Fortunately, this fixed the problem.

One last thing: I tried testing both the old and new diodes for conductivity and polarity using my volt-ohm meter (VOM), but I was unable to get either diode to "turn on," even though my VOM is powered by a 9-v battery, and I used the 2-Mohm range setting. I guess the test voltage of my el-cheapo VOM isn't high enough to exceed the diode's threshold voltage, (even though I have successfully used this same VOM to test low-voltage diodes).

removed a dozen screws-discarded large cap-replaced diode-replaced a dozen screws(took longer to replace them than remove for some unknown reason). Microwave now works(wife happy).

I UNPLUGGED the microwave and removed the cover, using a phillips and a Torx screwdriver for the machine screws. I set these screws aside, so as not to confuse them with the later encountered screws. I photographed the magnetron to assure proper placement of the 6 phillips machine screws involved in reassembly (marking the the locations on the old magnetron would do as well. I marked the old magnetron "old", to avoid later confusion. I removed the two screws holding the shields to the magnetron. I removed 3 of the 4 screws holding the magnetron to the microwave, leaving one of the top screws. I held the magnetron securely and removed the last screw, pulling out a the part of the magnetron that penetrated the microwave. I installed the new magnetron in reverse order. One problem I encountered was locating one of the six screws, which had been pulled into the old magnetron by magnetism.

unplug the unit then pull down , lot of screws are on top. open the cover . you could see the parts that need to replace on the right hand side (heavy side). disconnect wires then test the parts that need to replace by a tester to make sure that it's really broke .then unscrew part and replace .

hardest part was taking the microwave down off of the wall to gain access to the diode. Thought if was the transformer but ended up being just a blown diode. remove and replace and bench test. that part took 15 minutes . moral of the story don't boil water under the side of the microwave that holds the electric components.

I started by calling a reputable service company to diagnose my problem. The repair tech told me it was the magnetron and it was a "very difficult" repair that required two people because the over-the-range unit needed to be taken down. I asked for a detailed estimate. He quoted $550 including parts and labor. After he left, I researched the part costs on this site and realized his costs were very inflated. I purchased the magnetron for $220. It arrived at my door two days later. Installation was very easy. First, I unplugged the unit. Then, while my wife was making sure it did not fall off the wall bracket, I unscrewed the two mounting screws from the top of the cabinet. I lifted the unit down from the wall and set it on the kitchen counter. The shell needed removed from the microwave which involved about 20 screws. This provided access to the magnetron on top. The magnetron is secured by five screws and a plug. I unplugged it, unscrewed it, and removed the old part. Then, I installed the new magnetron, and tested the microwave to make sure this did the trick. It worked. I put the outer shell back on the microwave and cleaned the microwave. (This is a great opportunity to clean the areas you do not typically see!). I then remounted the unit and plugged it back in. Saved myself a bit of money so I took the family out to dinner and a movie to celebrate. Microwave was in working order for heating up left overs the next day! Thank you!!!

Information provided on the web site by Part Select, were helpful and encouraging to select and buy the part needed to repair the appliance. No doubt, a skilled person having background in the repair of appliances should attend such repair job.