Definition: Communication issue between the Main PCB and Display PCB.

Cause

Supply Voltage Issue.

Solution

Make sure the supply voltage to the unit is within correct range.

Check the spec sheet to see if the unit is 115V/208V/230V and that the actual supplied voltage +/- 10% of the rated voltage required.

Cause

Wiring issue between the Main PCB and Display PCB.

Solution

– Check that the wiring harness is fully seated and making proper

connection with both boards. (Some models may have more than 1 harness between the 2 boards, check diagram of specific model).

– Inspect harness for breaks or pinched wires. If issue is found replace the wiring harness.

– Reseat Connectors at both boards.

Cause

Defective PCB.

Solution

If no supply voltage or harness issues are found and reseating connectors does not resolve code, replace the Main PCB and Display PCB together.