LG LFX28968D Service Manual page 79

12-2 Check B
B1. LED blinks once, then repeats (FCT0 Fault)
Blink OFF Blink OFF
- Purpose: Detecting motor current and voltage error
- Check voltage at point A (Motor Voltage), point B (Motor Current) andPoint C (Capacitor
Voltage) when compressor is off .
- Spec: Points A, B, & C 2.5V ± 0.3V
Protection
Blink 1 time
logic
(FCT 0) Check B1
Check B
Out of spec?
(2.2 - 2.8V)
N
Reset Power
B2. LED blinks two times, then repeats (Stroke Trip)
Blink Blink OFF Blink Blink OFF
- Purpose: Prevent abnormally long piston strokes.
- Case 1. If compressor doesn't work and LED blinks - Cause: Possibly harness from compressor to PCB might be
defective.
- Case 2. If compressor works intermittently and LED blinks - Cause: Condenser Fan or Freezer Fan is not running. Sealed
system problem such as moisture restriction, restriction at capillary tube or refrigerant leak.
- Logic: Compressor is forced to off and then tries to restart after 1 minute.
Protection
Blink 2 times
logic
(Stroke Trip) Check B2
Check B
Compressor
Doesn't work
Replace
Driver PCB
N
OK
NG
Fix Cycle
Cycle Check E
Repeat
Check Procedure
Y
Replace Driver PCB
N
Harness
Y
Connecting
Check C
Compressor
Works Intermittently
Y
N
Stroke Trip Reset
Occur? Power
- 34 -
Protection Logic
Protection Logic
Fix Harness
Y
Y
Capacitor
N
Spec.
Check C
Y
Compressor
N
Damage
Check C
Y
GND
Voltage
B
A
C
Replace
Capacitor
Replace
Compressor