ACM1420AB (PACM1420AB0) Amana Microwave - Instructions

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).

The instructions on the website were incredibly easy and I saved myself a lot of headache by using this site.

-it was built in unit - so I needed to pull the decorative grill from around the outside to remove it from the wall
- removing the back of the case involved removing phillips head screws from along the side and back of the unit. the only issue I encountered on removing screws was the fact that the "torx / star" screws could not be fit with the wrench that I had (they had a pin in the center that would not allow the wrench to fit into the star). However, a pair of pliers was handy and they were removed just easily.
- I had ordered both the high voltage diode and magnetron because I didn't know which item was the problem. I grounded the diode with two screwdrivers while wearing rubber gloves to be safe. the warnings on this did the trick as it was the only scary part of the operation.
- the diode was a little hard to spot looking at the schematics, but is is found on the lower right corner of the right side of the panel and easily pulled out and replaced. I tried the microwave again to see if it worked...and it did not. So I confirmed that the magnetron was the issue.
- removing the screws for the magnetron and putting in the replacement was a dead easy and I tried the microwave again before putting cover back on. Worked like a charm. Super easy!

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).

Took microwave out of builtin cabinet with 4 screws.
Put microwave on center island and removed cover.
Tested interlock switch with volt meter and it appeared ok so I put my kit back in box and sent back.
Took out magnetron unit and replace with new part.
Put cover back on and test.
All is working and installed back in cabinet. Two weeks later all still working great.

It seems that the heat of the microwave cracks the part over time. It is a very simple installation.

Watched a you tube video prior to installing new switch. Followed the video which gave me confidence i was up to the task. After removing the touch pad I found my design was not exactly like the you tube model but I found the defective switch, replaced it and put the microwave back together. Works great. Again watch the videos

Using fingers, the old turntable roller guide was pulled up off the motor shaft. The plastic roller guide shaft coupler was found to be broken, allowing the motor shaft to spin without turning the roller guide. The hole in the floor of the oven was inspected, and no broken pieces were found which could interfere with the new roller guide. The new roller guide was then gently pressed down over the motor shaft. Very easy.

Remove from cabinetry, take cover off and had a very difficult time removing the plastic form that has the switched in. Replace the lowest of all the switches, and then again very difficult time getting the plastic form back in. Some of the plastic even broke during the process but not any that could prevent it from working as it did before. I had ordered a fuse, 2 packs of 2 switches as there are 3 switches but only had to use 1 to get it working again. Tested after switch install, put the cover back on and reinstalled in the cabinet.

took out plastic piece under plate (that was broken) and placed new one in the hole. No tools req'd. Works like new.

Ice covered the top back of the freezer compartment. This did not allow the cold air to move up to the fridge. Complete defrosting (36hrs) fixed the problem. There was a lot of water, from ice inside, that was not visible. We realized the freezer drawer must have been left cracked open. Thanks so much.

removed microwave cover screws, unplugged motor, screwed on new one

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.

The built-in microwave was removed by taking off the front plate that was secured by 3 screws at the bottom. The unit was moved to the side slightly so that the power cord could be disconnected. Then the entire unit was withdrawn. The outer shell of the unit was taken off by removing the six screws holding it in place. The shell may need to be shifted slightly to separate it from the unit. Once removed, the bracket latch and opening mechanism for the door was revealed. The latch is inserted simply by aligning the two nipples with the correponding holes in the opening mechanism and gently pushing it into place. The latch is plastic and appears to be vulnerable to breakage over time through constant use, so I have ordered a spare should the problem reoccur.

I called to make sure I was replacing the correct part. I paid over the phone and it came the next day. Very very easy process.

1. Remove the trim frame off of the front of the cabinet (4 Phillips screws). At this point, take glass plate and turntable frame out of unit. 2. Slightly lift the unit off the cabinet frame (which is attached to the cabinet) so the feet on the microwave allow the unit to clear the frame and then remove microwave from the cabinet. 3. Once slightly removed from the cabinet, unplug the unit before completely removing it from cabinet. 4. Take 2 Phillips screws out of the side panels. 5. Take about 6-7 T20 Star Pin screws out of the back of the panel. (This may require you to purchase this special tip if you don't have it in your toolbox). 6. Slide the microwave cabinet toward the rear of the unit (the front portion clips into the frame ... don't try prying it off because you'll damage the unit). 7. Completely remove the microwave cabinet housing. 8. Be careful not to damage or catch any internal wiring inside the unit while the cover is off. 9. Turn unit on it's back and remove 4-5 Phillips screws holding the bottom cover in place. Remove bottom cover. 10. Now notice that the turntable motor is completely exposed. 11. Remove the wiring harness from the motor (notice which connection clip has the black wire). 12. Remove the one Phillips screw holding the motor to the frame. 13. Clean around the area in case food spills may have gotten into the area. 14. Insert new motor, put Phillips screw back in and attach power connection. 15. From this point on, just reverse steps to re-assemble microwave and put back in cabinet. 16. Test new turntable motor. 17. Enjoy the smile from your wife because she can now use the microwave!