Daewoo Rf 420 Service Manual

FUNCTIONS
A. “TEMP” Button
 1. Temperature control of Refrigerator compartment
 2. 5 step mode of successive temperature mode
 3. Initial mode by power input: step “3”
 4. Temperature will be set if the button doesn’t get pressed again within 5 sec.
    - Whenever pressing “TEMP” button, setting is repeated in the order of
          “3” → “4” →  “5” → “1” →  “2”  (LED LAMP ON)
B. Temperature of Refrigerator Control
 1. COMP and FAN will be controlled by the on/off condition of each mode.1
 2. Temperature...

FUNCTIONS
Defrost Mode
A. When total operation time of compressor becomes: 6, 8, 10, 12 hours.
  - any error mode-R1, D1, F3, C1, RT/S, Door SW error- happens.
  - or, running rate of COMP (per 2hrs of total operation time) is more than 80%.
  - or, total door open time is over 3 minutes.
  - or, ambient temperature (RT) is more than 40C.
B. Even if the above condition “A” is not satisfied,
  - Defrost mode starts immediately when total operation time of COMP is 14hrs.
  - or, defrost mode starts...

A. When initial power input or returning power failure.
    if the temperature at the Defrost Sensor is below 3.5 C, Defrost Mode starts.
    ( It prceeds from PRE-COOL ),  [ PRE-COOL - Heater On - Pause (10min) - Normal Operation ]
B. Initial defrost mode starts after Prevention of Compressor Restart. ( Refer to function No. 5 )
FUNCTIONS
 Initial Defrost
 Flow Chart of Defrost Start
Defrost Mode
CONTROL OBJECT INPUT
 Total COMP Work Time / COMP Working Rate
 Total Door Open Time   / RT
 3. Defrost...

FUNCTIONS
R-HTR
COMP
A. Condition of LOW RT
  - LOW RT Period : RT sensor below 19C
  - When the temperature of RT sensor is over 20C, the system comes to be “General Operation Mode”.
  - When the temp. of RT sensor is between 19°C to 20C, the system keeps the previous mode.
B. Control
  - When Comp. is on, R-HTR is off.
  - When it passes 6 min after COMP is off, R- HTR is on.
  - COMP can’t be on within 30 min after COMP is off.
       ; COMP doesn’t work at the steps “Heater On” and “Pause”  of...

FUNCTIONS
 Buzzer
A. HOW TO REDUCE
    -   1 min : Click FAST KEY one time on MAIN PCB.
    - 30 min : If you press FAST KEY continuously, you can reduce 30 minutes on each 2.5 seconds with
buzzer.
B. Practice Use : Can be applied to reduce needless time on test.
    EX
) function of stop for 6 min
CONTROL OBJECT INPUT
 ”FAST KEY”
7. Time Reduction
Display Panel
A. START : by pressing “TEMP” and “S-COOL” buttons for 5 seconds.
B. CONTROL :
   - All electronic compartments are off except “Display Panel”....

FUNCTIONS
Control Resistance of R sensor OFF Point
A. LOW COOLING OPTION ( Weak Cooling )
    - When the refrigeration of refrigerator is poor or weak though Fan and COMP are working continuously,
         the following actions are recommended for service.
         
- Resistance (R47) :  Default resistance (31.4Kohms)
              - Resistance (R45) :  Cut the “J1” off to reduce basic resistance by 1.5°C. (2Kohms up)
              - Resistance (R42) :  Cut the “J2” off additionally to reduce basic...

FUNCTIONS
B. Prevention OPTION of EXCESSIVE OR LOW COOLING.
 
;  The input voltage of MICOM and R-Sensor ON/OFF point by changing J3 & R30.
 
OPTION 3
(P63)  26PIN
CC3 J3 R32 R31
R30MICOM 5VVa
 Input voltage of MICOM
 R-sensor ON/OFF Point
CONTROL OBJECT INPUT
  ”J3” & “R30” On Main PCB
 9. Control of R-sensor OFF Point
+1.7C 5VJ3(CUT), R30(NO USE)0.3C 2.0C 11+1.4C 4V
J3(CUT), R30 (40.2kohm)0C 1.7C 10+1.1C 3.3V
J3(CUT), R30 (19.6kohm)-0.3C 1.4C 9+0.7C 2.5V
J3(CUT), R30 (10kohm)-0.7C 1.0C 8+0.4C 2.0V...

FUNCTIONS
 Input voltage of MICOM
 R-sensor ON/OFF Point
C. Changing Difference between R-sensor “On” point and “Off” point.
 
 ; The input voltage of MICOM and R-Sensor ON/OFF DIFF. by changing J4 & R23.
 
CONTROL OBJECT INPUT
  ”J4” & “R23” On Main PCB
9. Control of R-sensor OFF Point
OPTION 2
(P64)  27PIN
CC6 J4 R28 R25
R23MICOM 5VVa
3.9C 5VJ4(CUT), R23(NO USE)-1.4C 2.5C 113.5C 4V
J4(CUT), R23 (40.2kohm)-1.4C 2.1C 103.2C 3.3V
J4(CUT), R23 (19.6kohm)-1.4C 1.8C 92.8C 2.5V
J4(CUT), R23 (10kohm)-1.4C 1.4C...

FUNCTIONS
 LED Lamp
- ERROR DISPLAY
   - To confirm error happens or not, push S-COOL” button for continuously and “TEMP” button 5 times.
   - To stop the Error Display Set, push “TEMP” button 1 times, or wait 4 minutes.
   - After operations back to normal, the displays come to be reset.
A. R1 ERROR
  (It happens when R-Sensor is OPEN or SHORT)
 -  DISPLAY : STEP “3” LED is on & off continually.
 -  CONTROL :
    ; Controlled by the following condition of RT
    ; When “RT ERROR” happens at the same...

11. Function Key Summary Table
( 1 - 2 - 3 - 4 - 5 - 1 ) Forced Defrost Mode
Pull Down Mode
Error Display
Demo Mode
Display
 In Error Mode, you can find the current mode ( What mode is operationg ) and what kinds of Error happen.How to terminate Temp + S-Cool button for 5 seconds
LED Lamps will be on as next steps. Display 4, 5 LED flicker (When no error happens)
How to enter the Mode Temp + S-Cool button for 5 seconds How to enter the Mode S-Cool + Temp button 5 times
How to terminate emp button 1 time...