MR5493G Microwave - Instructions

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 ... Read more 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!

Removed control panel, discharged HV capacitor. Removed old diode, tested to confirm failure. Replaced part. Other than the removal of the panel swapping the part was almost as easy as replacing a light bulb.

I removed the outer cover and exposed the inner workings. I watched a video on partselect.com to show how to remove and replace the Diode. I followed the instructions and it was very easy to replace.

Unfortunately, the diode was only part of the issue. I ended up replacing the High Voltage capacitor and Magnetron also. Those w ... Read more ere a little more complicated but still easy to do.

Now the Microwave works just like new! Cost me less than $100 for all parts.

The high voltage tired was shorted. I replaced it with a new one, but that did not solve the problem.

You can test the high voltage tired with a voltmeter and a 9 V battery. Search Search for it on YouTube.

You can also test the high voltage capacitor, the high-voltage transformer, and the magnetron with a multi met ... Read more er. Search for the procedures on YouTube.

I tested all these high-voltage components with a low-voltage multi meter, and they all checked out OK (after replacing the diode). However the microwave still did not heat food.

When working on a microwave it is important to unplug it and also discharge the high voltage capacitor. The capacitor has a 10 megaohm resister to automatically discharge itself, but it may have failed – – so discharge it manually.

In the end I ordered a new microwave.

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.

Snipped four corners off inspection panel,removed one phillips screw and two elect. Connections. Reverse process.

Other tools that are usefull long needle nose pliers, long thin blade screw driver and small magnetic flashlight. Place the microwave on a work bench and remove the case it cover 3 sides. Place the microwave on a chair so it can stand with the controls up. You are replacing the lower door microswitch. The switch is located behind the ... Read more control panel in the lower part of the area. The switch is several inches inside this area and your hands will not fit. Take care when moving wires and a couple of sensors. Use the thin blade screwdriver to release a tab holding the switch in place. Do not break this tab. Take the needle nose pliers and remove the switch. Put the wires on the new switch, open the door a short distance so a door lever moves enough to put the microswitch back into the bracket.

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 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."

... Read more />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).

I used my pocket knife to open the package. I opened the door and removed the plate and set the guide down and put the glass plate back.

Set it in the oven, wonderful!!!!!

Pretty easy tear down and assembly once I removed it from cabinet (built in micro)

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.

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.

Simple replace