It appeared that the water inlet valve was not closing fully and was allowing water to continue to trickle into the icemaker.
I melted the ice surrounding icemaker & freezer with a hair dryer. Then dried off the inside of the freezer and lubed the rails on the pull-out freezer drawer, etc. with food grade silicone. I installed a new water inlet valve and reconnected the water inlet. After the ten-minute installation, everything is working perfectly and we saved a very expensive service call.