MS1040BB 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 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!

Only had to set the new turntable in place. I was very impressed by the quickness in receiving the part.

First I removed upper front grill by removing two Philips head screws on top and pulling off. This exposed the Philips head screw which holds control panel in place. After removing screw I pushed up on panel and it came off to expose fuse. With needle nose pliers I removed old fuse and again with pliers held new fuse in position. With the help of a bladed screwdriver, I pushed new fuse into holder, then replaced panel, screw and grill. This took less than 15 minutes even as one of the wires on control panel pulled out of connection and took some time to locate where to reconnect, otherwise was an easy fix
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Found instruction on internet,
1. Remove anit-tampering screws with punch and hammer
2. Remove the rest of the screws
3. Removed cover
4. Remove burned out bulb and installed new one
5. INstalled cover
6. Installed screws including the anti tampering onces
7. Op tested unit.
Wife is happy.

Jenn-Air Microwave would not turn on. Clock worked , light worked, timer worked and would count down .I changed' Part #0813140 Switch, Micr} cost $8.99 plus shippingNow it works Thank You for good advise

Removed 4 small star head screws from back of microwave, lifted body off, removed blown fuse and replaced with new one (found where cord enters). This model is stainless inside and out and I like it a lot. It is also sold by Daewoo and a few other manufacturers.

Replaced diode works great. your website said 92% diode was problem and it worked. Order fuse in case old was blown did not have to use it.

We have a Jenn-Air microwave and oven combination that is installed as a "stack" in a cabinet. The light bulb had burned out, and I read some of the posts on the partselect.com site about how others performed this replacement; ours was a bit different.
To replace the microwave light bulb, we had to remove the entire microwave and oven stack from the cabinet. There were four anchor screws on the sides (two on each side) of the microwave that were driven in perpendicular to the face of the microwave. There were four more screws that were on the sides of the oven that could be accessed once the oven door was open.
With those anchor screws removed, we had to carefully pull the entire microwave / oven stack from the cabinet to reach the top cover of the microwave. We used an old wooden crate to hold the front of the oven and left the back of the oven resting in the cabinet enclosure. This gave enough room to access the screws on the top cover of the microwave, without having to lift the entire stack down to the floor.
At this point, I could unplug the microwave power cord, which was plugged in to a socket built into the top of the conventional oven part of the stack.
The top cover of the microwave was attached with regular Phillips head screws, so those were easy to remove. Several other instructions indicated I would need a torx or star drive screwdriver, but I did not.
Once the screws were removed from the top cover of the microwave, the cover can slide rearward to be removed. However, there are two metal strips that run vertically along the sides of the microwave and at the top of the microwave, these bends over at a right angle over the top of the microwave. The top cover has tabs that sticks up vertically from the cover, so that the bent strips prevents the cover tabs from passing as the cover is slid backwards. The vertical strips have several screws connecting it to the body of the microwave. On one of the vertical strips, I removed the two of these screws closest to the top of the microwave. Then, I gently pushed a wood chisel, because of the bevel angle, between the vertical metal strip and the microwave body. This moved the bent-over portion of the vertical strip far enough away from the microwave that the tab on the top cover cleared the strip, and I could then remove the top cover.
With the top cover removed, I could see the old light bulb. It is attached with a push-in electrical connection that was easily pulled off. One Phillips head screwdriver held the old bulb in place towards the rear of the microwave. Towards the front of the microwave, a small plastic post holds the front of the bulb. I removed the screw and pulled out the old bulb.
The new bulb fits easily into the same plastic post and screw connection. However, the new bulbs connector prongs are bent at a 90 degree angle to the original bulb. Instead of sticking straight out from the microwave, which was how the old bulb was configured, the new bulb prongs pointed to the right side of the microwave (as viewed from the front). Fortunately, the wiring harness in the microwave that connects to the light bulb had a zip tie that was loose enough to get enough slack for the push-in connector to reach the new bulb's prongs.
After the bulb was in, I reversed the steps described above, making sure to leave the chisel in place until the top cover had been secured back in place. Once the chisel was removed from the vertical metal strip, the bent portion again would prevent easy removal of the top cover. I made sure to plug the microwave power cord back into the outlet on the conventional oven, then we slid the entire unit back into the cabinet enclosure, and I put the anchor screws back to hold the stack into the cabinet.
Three of us worked on this - mostly to help pull the stack out of the cabinet and to help steady it while the front was resting on the wood crate. This is not a single-person job. It was not terribly difficult, but the number of steps is very tedious. I found a helpful YouTube video "How to uninstall/install a Jenn-Air JMC8127DD/JMC8130DD Microwave Oven" posted by Ali The Handy Man. Being able to see that the microwave and oven stack was connected by a "bridge" (as Ali calls it) was a major help in tackling this.
After this, we suspect that Jenn-Air must have not wanted any repairs to their appliances. As I said above, this repair to replace a light bulb seemed unnecessarily tedious.

I mistakenly thought I had to remove the microwave to get to the back, not so. I would have had access to what I needed to unscrew; but I have to admit the hassle of taking it down and putting it back equals having to work on it attached to the shelf-your call on how you do this. I unscrewed the front top to remove the vent piece that is across the top front of the microwave. This will reveal the control panel screw. (While you have the vent removed you might want to clean the vent and the exposed filter.) carefully lift and pull out control panel. I unplugged a piece as the wires were tied tight. It will not completely detach, so carefully tip it back from exposed insides. The fuse is not clear but white with silver ends so look in upper right for it. I popped it out and replaced it. Replugged the wired part to cover and carefully fit tabs in and slide down to secre. Replace screw, replace vent piece and secure screws on top of microwave. I plugged it in to test before putting it back above my stove.

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.

remove outer cover of microwave, (special recessed star bit required) change bulb, unplug and remove 1 phillips screw.

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 meter. 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.

Access is via RT. SIDE Panel as you face microwave. There are three screws on the bottom right edge to loosen. After that the side panel slips down and off. the fuse is located in the rear near where the power cord comes in. It is the white ceramic tube 1/4" in dia. and 1-1/2" long. Pull it out like any fuse and replace with new one. Reassemble and you are done!