Frigidaire Refrigerator to Cold

[TechnicianBrian]

Model # PHSC39EHSS2, the complaint on this newly purchased unit was the fresh food section was to cold and freezing everything inside. A quick look at the temperature display confirmed the problem with an indicated temperature of 25 degrees F, entirely to cold for most refrigerated items. Figuring I was dealing with an airflow issue, I started my trouble shooting in that area. But before we go there, let's understand how our side by side refrigerator cools.

Making it Cold
In most home refrigerators, the cooling process takes place within the freezer section where the evaporator coils are located. A fan will circulate chilled air around the cavity and into the fresh food section. Cold air being denser than warm air, will pushing ahead of it any warmer air that has absorbed heat from within the fresh food cavity. This air will return to the freezer section via one or more air return ducts where the heat will be removed by passing by the evaporator coils as it makes it's way through the air passage again. But this method of cooling needs to be controlled or the fresh food side of the unit will quickly become as cold as the freezer section, and that is where the air damper comes in to play.



Controlling the Air
The air damper or diffuser as it is often called, is simply an opening to the fresh food section that can control how much air is circulated from the freezer section. By controlling this airflow, the damper is directly controlling the temperature of the fresh food section, and indirectly controlling the temperature in the freezer by holding in more cold air. Dampers come in many forms and may be simple flaps, shutters, doors, or wedges that can increase or decrease the amount of air allowed to pass. They may be controlled by a motor or directly connected to a temperature selector via a push rod assembly. Whichever form they take, there purpose is to control the airflow that enters the fresh food section.

We now Return
With the damper looking to be the problem, I removed the cover and found the damper door in the full open position allowing unrestricted cold air into the fresh food section. Because the temperature display indicated well below the selected set point, this indicated I either had a control board issue (not able to control the damper motor) or a failed damper (control signals present, but the motor doesn't respond) itself. The damper in this unit utilizes a bi-polar stepper motor to open and close the damper door and it is directly controlled by low voltage driver circuits on the control board. Because this kind of motor requires separate logic in order for it to operate, you cannot simply do a voltage check using your meter to verify power to the motor. You can however, verify whether the motor is good or bad by checking for resistance between each of the wires at the motor. If you read an open circuit between any two of the wires, you have an open winding and the motor is bad. If the motor tests good, use the available diagnostic test (which Frigidaire doesn't put on the tech sheet) to test the operation of the motor by the control board. If the motor tested OK but it fails in the diagnostic test, the control board is the problem.

Service Diagnostics
To enter the test mode, press and hold the Freezer Temperature UP (Warmer) key
while pressing the Freezer Temperature DOWN (Colder) key 3 times within 5
seconds.
The freezer display will show �1�. The fresh food display will be blank. Each press of the freezer temperature up (Warmer) or the freezer temperature DOWN (Colder) key will step you through the service menu tests,�1� through �8�.
Each press of the fresh food temperature UP (Warmer) or fresh food temperature DOWN (Colder) key will step you through variables of each test.



A Simpler Solution
Fortunately for me, the motor and control tested OK, it was the plastic mechanism between the motor and the damper door that had broken leaving it in the full open position. By replacing the damper, I got this unit back up and running in no time. Now the refrigerator is only as cool as it needs to be.


Frigidaire Refrigerator Damper Assembly Part # 241518501

[Repair-man]

I understood everthing but those diagnostic tests...looks Greek to me 

The freezer display will show “1”.

[Al Capone]

Text error, it has been repaired.

[JWWebster]

Hay brian do you know why a brand new LG would not be running and have O FF on the display? Someone in here has a problem. Seems to me like it is saying I am off turn me on. Which magic buttons do you push? Do you have to be standing on your head while doing it?