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.

***If supply voltage is correct…

Disconnect power for a few minutes to reset the unit***

Cause

PCB Defect.

Solution

If code returns after reset…replace the Main PCB and Display PCB together.