Kenmore side by side not cooling

Freezer not cooling, checked evaporator and there is ice on top coil and bottom two coils. The rest of the evaporator is clean (no frost). I bypassed the defrost thermostat by cutting it off and jumping the wires - defrost heater did not come on so I replaced the thermostat. I then put it in diagnostic mode to test the heating element - it DID turn on and melted the ice. Does this mean my board is bad?