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Do you clear the drain line so that you know water can get to the pan under the refrigerator?
The drain line itself may be clogged with dirt and/or ice.
When clearing the drain line you would use a turkey baster with hot water. Keep putting hot water in and removing it until the water goes all the way down to the drain. Afterwards, you can pour a diluted solution of bleach and water thru the drain kill any bacteria and/or fungus that may have accumulated.
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