Whirlpool defrost problems

Whirlpool Gold Series side by side coils in freezer Ice up, refrigerator gets warm. Replaced bi-metal thermostat and heater and thermistor and fan test good. Is there anyway to test the pins Voltage on the UI control board for a faulty defrost timer? And or, anyway to test voltage on the main control board to determine which board is bad? Is there be anything else that can be tested?

Here are your parts
Parts for Whirlpool GS6NBEXRB02 Refrigerator - AppliancePartsPros.com

See the attachment for the tech sheet.

Did you check any of the parts that you replaced with a meter before replacing them

Try forcing a defrost see the tech sheet.
Note that the defrost thermostat must be frozen for the defrost heater to come on. If the heater comes on then the main control board needs replacing as it is not programming a defrost cycle. Be careful that you do not burn your fingers.

If the defrost heater does not come on. Unplug the unit and check between P1-3 and P1-2 at the control board. It should be about 20 ohms (heater resistance). If this is OK then I would replace the main control board.
GS6NBE.pdf (1.3 MB)