How do I fix error code E Sd on a LG refrigerators?

1. undefined: Check all loose connections between Main PCB and Sub PCB. Reconnect any loose connectors. 2. undefined: Measure voltage at Sub CON1 pins 8–33. Expected: not 0 or 5 V. If 0 or 5 V, check Sub PCB connection (possible loose connector) and replace Sub PCB if connection is secure. 3. undefined: Measure voltage at Sub CON1 pins 10–33. Expected: not 0 or 5 V. If 0 or 5 V, check Sub PCB connection and replace Sub PCB if needed. 4. undefined: Measure voltage at Main CON3 pins 1–15. Expected: not 0 or 5 V. If 0 or 5 V, check Display PCB connection (loose connector) and replace Display PCB if connection is secure. 5. undefined: Measure voltage at Main CON3 pins 3–15. Expected: not 0 or 5 V. If 0 or 5 V, check Display PCB connection and replace Display PCB if needed. 6. undefined: If all voltages are correct, explain normal operation to customer.

LG Refrigerators

Error Code E Sd

Sub PCB Communication Error — Main MICOM and Sub MICOM

Moderate

Address soon - your appliance may not work properly

How to Fix

1
Check all loose connections between Main PCB and Sub PCB. Reconnect any loose connectors.
2
Measure voltage at Sub CON1 pins 8–33. Expected: not 0 or 5 V. If 0 or 5 V, check Sub PCB connection (possible loose connector) and replace Sub PCB if connection is secure.
3
Measure voltage at Sub CON1 pins 10–33. Expected: not 0 or 5 V. If 0 or 5 V, check Sub PCB connection and replace Sub PCB if needed.
4
Measure voltage at Main CON3 pins 1–15. Expected: not 0 or 5 V. If 0 or 5 V, check Display PCB connection (loose connector) and replace Display PCB if connection is secure.
5
Measure voltage at Main CON3 pins 3–15. Expected: not 0 or 5 V. If 0 or 5 V, check Display PCB connection and replace Display PCB if needed.
6
If all voltages are correct, explain normal operation to customer.