I have a KitchenAid Microwave KBHS109SSS01 I am testing for a friend. When Powered the light comes on if the door is opened but the keypad and the display are not functioning. From the tech diagram them problem seem likely to be the control board power transformer (9760213) or the control board itself.

I have measured the voltage over the 3 secondaries but can not find any reference values. I believe there to be an issue with at least the blue set as voltage is low and fluctuating but am not sure without a diagram for the touchscreen, keypad , or transformer itself. Below are the measured values for the 3 secondaries. If anyone knows the voltages on the secondary side of the UI Transformer I would like to compare before purchasing random components to try to fix.

The tech sheet does not have a resistance or voltage test on this UI / Control Board Power transformer only a test for the MW Light Transformer.


Secondary 1
Red 1 - Red 2 - 38.24 V

Secondary 2
Yellow 1 - Yellow 2 - 1.880 V
Yellow 2 - Yellow 3 - 2.050 V
Yellow 1 - Yellow 3 - 3.930 V

Secondary 3
Blue 1 - Blue 2 - varying between 275 - 339 mV

The control transformer is receiving ~124V AC. DC output is 1.6mV on the red and 43mV on the blue. I was under the assumption this was an AC transformer with voltages indicated on the first post.

However, the light can not be powered by this UI / Control Board Transformer when the source plug (left side of picture) is removed the inside light remains on. See attached pictures. Sorry about the flash in the second picture but as you can see the transformer is unplugged.





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