My refrigerator is a model CFSP5RKBBSS. The ice cubes stopped forming and dumping. I had tried replacing the Icemaker (WR30X28693), the water valves (WR57X33326) and the Fan Duct (WR60X10330) but these were not the root cause of the problem.

Instead it was a bad Ice Box thermistor, which is not shown as a serviceable part in the GE diagram (it is foamed directly into the door of the fridge) which then once failed caused the control board (WR55X11098) to fail, the output voltage to the Fan Duct was only 2VDC, should have been closer to 14VDC, causing the temperature in the cube door to be above 32F.

I replaced the thermistor ($15) by cutting off the wires feeding the wiring harness and splicing in a new thermistor (WR55X10025), then replaced the control board ($150) and all is well.