Posted by Sr Tech Brian on 6th Jan 2020
Norcold N7X/ N8X Flashing 10 times/ Communication Fault (how to fix!)
FLASH PATTERN 10
Norcold N7X / N8X Communication Fault
The red light flashes ten times, goes off for 5 seconds and repeats. The display (optical) board and the main control board (power board assembly) have lost communication. They talk over one blue wire in the main wire harness, so that’s what you’ll test.
Before you start
- Note the code. Count the flashes twice to be sure it’s 10 and not 8 or 9. Those point to different faults.
- Stay safe. Turn the fridge OFF and disconnect 120V and 12V before unplugging the harness.
- You’ll need a multimeter with a continuity (beep) setting.
STEP 1
Check the blue wire connections
In the main wire harness, find the blue wire. Make sure it’s fully plugged in at both ends: pin P1-14 on the power board and pin P1-3 on the display (optical) board.
Is it fully plugged in at both ends?
Correct the connections
Seat both connectors firmly, then reset the fridge (OFF, then ON) and see if the code clears.
STEP 2
Test the blue wire end to end
Unplug the harness from both the power board and the display board. Set your meter to continuity and touch one probe to each end of the blue wire.
Does the blue wire have continuity?
The wire is broken
The blue wire is open. That wire runs through the main wire harness inside the cabinet, so Norcold’s fix is to replace the refrigerator. Talk to a tech before you decide.
STEP 3
Check for a short to ground
With the harness still unplugged, check for continuity between the blue wire and ground (bare metal on the fridge frame).
Is there continuity to ground?
Shorted to ground
The blue wire is shorted to ground. That wire runs through the main wire harness inside the cabinet, so Norcold’s fix is to replace the refrigerator. Talk to a tech before you decide.
STEP 4
Check for a short to other wires
Check for continuity between the blue wire and each of the other wires in the harness, one at a time.
Is there continuity to any other wire?
Shorted to another wire
The blue wire is shorted to another wire in the harness. That wire runs through the main wire harness inside the cabinet, so Norcold’s fix is to replace the refrigerator. Talk to a tech before you decide.
The wire is good. Replace the power board
Plug the harness back in at the power board and the display board, then replace the main control board (power board assembly).
Norcold Power Board 639593 →Main control board for the Polar N7X and N8X.Based on the Norcold Polar N7V/N7X/N7LX/N8V/N8X/N8XL service manual, Fault Code Flash Pattern 10.