LG LRFD21855ST, Service Manual

8-1-16 TEST Mode

1. The Test mode allows checking the PCB and the function of the product as well as finding out the defective part in case of

an error.

2. The test mode is operated by pressing two buttons at Display panel.

3. While in the test mode, the function control button is not recognized, but the recognition tone (beep~) sounds.

4. After exiting the test mode, be sure to reset by unplugging and then plugging in the appliance.

5. If an error, such as a sensor failure, is detected while in the test mode, the test mode is cleared and the error code is

displayed.

6. While an error code is displayed, the test mode will not be activated.

* Freezer Fan RPM Variable Check:

In case the freezer fan is in operation when the express freezer button and freezing temp. button. Control are pressed for
more than one second at the same time freezer fan RPM changes. (for example if high speed, to normal speed or if
normal speed, to high speed for 30 seconds) 
After 30 seconds, it turns to its original RPM.

* Demonstration MODE:

1. When the express freeze button and the refrigerator temperature control button are pushed at the same time and hold

for 5 seconds or longer, it converts to demonstration mode.

2. The Display shows the Demo graphic.
3. In this status, all Loads are off (Compressor / Fan / Damper / Heater)

(Even is Demonstration Mode, the refrigerator Lamp automatic off function warks normally and can be demonstrated)

4. Exit the Demo mode and reset the Display by pressing the Freezer Temp. Control button and the Refrigerator Temp.

Control button for 3 seconds or longer.

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MODE

MANIPULATION

CONTENTS

REMARKS

TEST1

TEST2

TEST3

Reset

Push Express Freezing

Key and LOCK KEY at the

same time for 3 seconds

OR Push TEST S/W(on

the main Board) once.

Push Express Freezing

Key and LOCK KEY at the

same time for 3 seconds

in TEST MODE 1 OR

Push TEST S/W once in

TEST MODE 1

Push Express Freezing

Key and LOCK KEY at the

same time for 3 seconds

in TEST MODE 2 OR

Push TEST S/W once in

TEST MODE 2

Push Express Freezing

Key and LOCK KEY at the

same time for 3 seconds

in TEST MODE 3 OR

Push TEST S/W once in

TEST MODE 3

1) Continuous operation of the

COMPRESSOR and the Freezer fan

2) Stepping DAMPER OPEN

3) Defrosting HEATER OFF

4) DISPLAY LED all ON

1) Continuous operation of the

COMPRESSOR and the Freezer fan

2) Stepping DAMPER CLOSE

3) Defrosting HEATER OFF

4) DISPLAY LED shows no. 2

1) COMPRESSOR and the Freezer fan

OFF

2) Stepping DAMPER CLOSE

3) Defrosting HEATER ON

4) DISPLAY LED shows no. 3

Reset to the previously setting 

Before TEST MODE.

Reset if the

Temperature of the

Defrosting Sensor is

46°F(8°C) or more.

The compressor will

Start after a 7-minute

Delay.