• ** 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

    Jake

KitchenAid Model KHMS2050SSS2 Microwave intermittently beeps

Airnupe

Premium Member
Joined
Aug 3, 2019
Messages
9
Location
Raleigh
Model Number
KHMS2050SSS2
Brand
KitchenAid
Age
6-10 years
Over the last couple of months, our KitchenAid microwave/hood combo will randomly beep and the display panel changes by reducing the power to 20%. Once I unplug the unit, it solves the problem momentarily, and then the unit may start acting up again. The microwave still operates properly during this time. The control panel lock key is difficult to lock most of the time. When I can lock the control panel, the microwave may continue to beep half of the time it is locked. Some sites have recommended locking the control panel to tell which part is defective, however, I am not sure in my case. After resetting the circuit breaker, the unit has entered the test mode. Although, I do not get error codes, the test shows that all keys have failed (even though I can successfully press and highlight each Key). Need help in determining which part to replace.

Scott
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
102,155
Location
McMullen Valley, Arizona
Hi Scott,

@rickgburton is our expert on these, I'll see if he can assist you.

Jake
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
34,750
Location
Murray, Utah 84107, United States
Hi Scott, do this and tell me what's on the screen;

1. Unplug microwave oven or disconnect power.

2. Open the microwave oven door.

3. Press and hold OFF/CANCEL.

4. Plug in microwave oven or reconnect power.

5. Release OFF/CANCEL and close microwave oven door. NOTE: If the OFF/CANCEL key is pressed during this diagnostic routine, you will exit the test mode.
 

Airnupe

Premium Member
Joined
Aug 3, 2019
Messages
9
Location
Raleigh
Rick,
I get the KitchenAid start up screen when power is reapplied. The screen asks me if I want to set the clock. There is no tactile feel in the Off/Cancel button at all.

Scott
 

Airnupe

Premium Member
Joined
Aug 3, 2019
Messages
9
Location
Raleigh
No Error Codes that I can see. When I go to "More Choices" the individual keys are selected and show as pushed, but then show up as "failed Keys".
20190804_220030.jpg
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
34,750
Location
Murray, Utah 84107, United States
Airnupe said:
...display panel changes by reducing the power to 20%
Scott, can you explain what you mean here? I have the tech sheet for that machine but it's really not a lot of help for your problem. I believe the problem is the touchpad but I'm not 100% positive. There's no test points or checks I can give you. This is a complicated machine to diagnose because there's too many circuit boards. You need to be an electronics tech to understand the circuitry. Whirlpool knows this is a complicated machine and problems can be caused by more than one board failure, so if you look at the tech sheet, instead of supplying 10 pages of circuit diagrams and test points, their solution is to replace the most likely part and if that doesn't solve the problem replace the next most likely part. I haven't been able to locate a service manual for that machine and I'm not sure it be any more help. The reason I believe it's the touch pad is from past experience on other machines with similar problems. So it's basically my best guess.
 

Airnupe

Premium Member
Joined
Aug 3, 2019
Messages
9
Location
Raleigh
Basically when the microwave beeps excessively, there are two things that we notice with the microwave. First, the microwave display is normal, with the time displayed. Second, the microwave display changes to display cooking power setting to 20%. ( as if someone reduced the cooking power setting from 100 down to 20%). Next time it happens, I will take a picture of it. As I mentioned before, the touch pad works normally except when I try to lock it by pressing the Off/cancel. Half the time it won't lock by holding it for 5 seconds.

Thanks
Scott
 

robhouston

Premium Member
Joined
Feb 24, 2008
Messages
28
Location
Chester, NJ
I'm a little late to the party here, but I have the same machine that you have, and you'll see I've had similar problems in a recent thread. I agree with Rick------it's a complicated machine. The first thing to replace is what Rich has indicated-----the touchpad. There is also a User Interface Board in the door with the touchpad, and if a new touchpad doesn't resolve the issue, this is the next part to replace. Between the two, that should resolve the "ghost" beeps and keypad changes.

On the off chance you haven't already dug into the machine, be careful when removing and replacing the door. I actually invisibly crushed/damaged one of the small wires that go from the door to the machine, which is easy to do, and it caused me major confusion before I finally and recently figured it out.

In the meantime, I've ended up with an extra brand new User Interface Board, should you end up needing one, and I can give you a very good price on it. PM me if you are interested.

Good luck with it,

Rob
 

Airnupe

Premium Member
Joined
Aug 3, 2019
Messages
9
Location
Raleigh
Thanks. I may take you up on the user interface board if replacing the touch pad doesn’t work.

Scott
 

robhouston

Premium Member
Joined
Feb 24, 2008
Messages
28
Location
Chester, NJ
If you haven't started the repair, be careful when removing the choke (the black part around the inside of the door). For this model, it is difficult to remove and is no longer available. Be sure to remove the two screws on the bottom of the door first. Your best bet is to remove the door, remove those two bottom screws, remove the 3 screws and brackets from each side, then carefully pry the outer door from the inner door. The choke will either come off relatively easily or stay on the inner door frame, which is fine. The touch pad and UIB are on the outer door frame.

Good luck with it------in my opinion, this microwave is a pain to work on!
 
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