Norcold 121X series, Service Manual

Page: 67 / 100

S
ection
8
65
Cooling System Replacement
The cooling system has to be tested for proper
operation. Test results need to show that both
the freezer and the fresh food cabinet do not
cool in AUTO mode, AC manual mode or in LP
manual mode. Before attempting to test the
cooling unit make sure:

The refrigerator is leveled.

DC voltage input to power board is 10.5 to
15.4 volts.

AC voltage input to power board is 108 to
132 volts.

Both AC heaters draw amperage.

Gas pressure is 10.5 to 11.5 in. w. c.

The burner and the orifice are clean.

Flame appearance normal.

The flue is clean.

The flue baffle installed.

Ventilation is correct.

Intake vent is clear.

Exhaust vent is clear.

Both fans are operational.

Door gaskets are in good condition.

Doors are properly aligned.

Thermistor on the proper fin.

High temperature limit switch open.

No cooling fault code stored in Diagnostics,
screen 5. See Figure 8-2, page 63.
Cooling Unit Testing
The cooling System Diagnostic Flowchart on
page 66 through page 67 provides sequential
steps to troubleshoot the cooling system.
Before attempting to replace the cooling
system:
1. Make sure the conditions listed in Cooling
System Replacement section are met.
2. Power on the refrigerator.
3. Set MODE to the AC manual mode or the LP
manual mode.
4. Set TEMP SET to setting 9 (coldest).
5. Place digital thermometer probe or
thermometer immersed in a container of
water on the left freezer shelf, against the
evaporator plate.
6. Power off the ice maker - units with ice
makers
7. Set the controls to Diagnostics.
a. Navigate to screen 3, fin temperature.
b. Record time and fin temperature.
8. Allow the refrigerator to operate for eight
hours with all doors fully closed.
Replace cooling unit when all of the following
are met.
1. No temperature change in Diagnostics mode
screen 3.
2. The no cooling fault stored in Diagnostics
mode screen 5, (segment 7).
3. High temperature limit switch is open and
fault L1 oP displays.
4. The leveling chamber is extremely hot and
absorber coils are at ambient temperature
(approximately).