Premium PRN438HW/S User manual

REFRIGERATOR
Service manual
NO FROST
MODEL:PRN438HW/S & PRN520HW/S

NOTE: product specifications are subject to change.
■Parts Description

■Circuit diagram

■Cooling diagram
■The guide for Disassembly Common parts of Refrigerator
◆The instruction of replacing the main board.
1. The location of the
electrical main board.
2. Unscrew electrical
box cover ( 2 screws ).
3. Remove the
electrical cover.
4. Tidy up the electrical
wires.

5. Unplug the electrical
wires and remove the
screw fixing the main
board.
◆The instruction of of replacing display board.
1. The locat ion of the
display board.
2. Remove the display
cover.
3. Unplug the electrical
wires and remove the
screws fixing the
display board.
4. Replace the new
display board.
◆The instruction of of replacing fan motor.
1. Remove the fan the
shelf part.
2. Unscrew two screws
of the wind channel
part in freezer
chamber.

3. Remove the wind
channel part in freezer
chamber.
4. Unplug the electrical
wires and remove the
fan motor part.
5. Unscrew the fixing
screws of the fan motor
and replace it.
◆The instruction of replacing refrigerator lamp.
1. The locat ion of the
refrigerator lamp.
2. Remove the lamp
cover and unscrew the
one screw then take
out the lamp.

◆The instruction of replacing Door switch.
1. The location of the
door switch.
2. Take out of the door
switch.
◆The instruction of replacing PTC Starting relay and Overload protector.
1. The location of the
PTC Starting relay and
Overload protector.
2. Take down Spring
Tap and Cover.
3.
Disconnect the
connect ing wire of the
PTC Starting relay and
Overload protector.

■TROUBLESHOOTING
◆The solution for digital display code problem:
No. Problems analysis Solutions
1
The D1 digital display
flashing when open the
refrigerator door.
1. The refrigerator chamber
Tem. Sensor is open circuit or
short circuit.
2. The refrigerator chamber
Tem. Sensor is bad.
3. The control PCB is bad.
1. Using a Multimeter with the
ohm switch to measure the
resistor of sensor or checking the
connect ing is well or not.
2. Change the sensor
3. Change the control PCB
2
The D2 digital display
flashing when open the
refrigerator door.
1. The freezer chamber Tem.
Sensor is open circuit or short
circuit.
2. The freezer chamber Tem.
Sensor is bad.
3. The control PCB is bad.
1. Using a Multimeter with the
ohm
switch to measure the
resistor of sensor or checking the
connect ing is well or not.
2. Change the sensor
3. Change the control PCB
3
The D3 digital display
flashing when open the
refrigerator door.
1. The Evaporator Defrost
Sensor is open circuit or short
circuit.
2. The Evaporator Defrost
Sensor is bad.
3. The control PCB is bad.
1. Using a Multimeter with the
ohm switch to measure the
resistor of sensor or checking the
connect ing is well or not.
2. Change the sensor
3. Change the control PCB
4 The
D3 digital display
flashing when passing key.
1. The electrical wire between
the control and display PCB is
open circuit or short circuit.
2. The display PCB is bad.
3. The control PCB is bad.
1. Using a Multimeter with the
ohm switch to measure the
resistor of electrical wire or
checking the connecting is well or
not.
2. Change the display PCB
3. Change the control PCB

D1 digital display D2 digital display D3 digital display D4 digital display
◆The common problem judgement method
Problem Cause
Refrigerator can’t start
1.1 Is the power cord connecting well？
1.2 Is the power voltage too low？
1.3 Is the sensor irrational setting?
1.4 Is the ambient temperature too low?
1.5 Is the circuit on power?
1.6 Is there some default in compressor
1.7 Is the refrigeration system blocked by ice or dirty, please stop the unit and restart
after 10 minutes to see if the compressor can start.
Weak cooling effects
2.1 Is there any heat source around the refrigerator?
2.2 Is there enough space around the refrigerator for reject ion of heat?
2.3 Is the setting of the temperature appropriate?
2.4 Is there too much food or overheating food in it?
2.5 Does there open the door frequently?
2.6 Is the door completely closed?
2.7 Does the gasket destroyed or distort?
2.8 Does the gas leak?
The unit can not stop
running
3.1 Is there any heat source around the refrigerator?
3.2 Is there enough space around the refrigerator for reject ion of heat?
3.3 Is the setting of the temperature appropriate?
3.4 Is there too much food or overheating food in it?
3.5 Does there open the door frequently?

3.6 Is the door completely closed?
3.7 Does the gasket destroyed or distort?
3.8 Is the thermostat good operation?
3.9 Does the gas leak?
Ice up in the freezing
chamber
4.1 Is the setting of the temperature appropriate?
4.2 Is there multi-moisture food and too close to the back wall of the refrigerator?
4.3 Is the ambient temperature too low?
4.4 Is the electric parts on good condition, specially the thermostat which will cause the
unit non-stopping .
Abnormal noise
5.1 Is the refrigerator stably placed?
5.2 Does the refrigerator bump other objects?
5.3 Whether the internal accessory of the refrigerator is in the right place.
5.4 Whether the water plate of compressor is fall from the unit.
5.5 Does the tube of the refrigeration system bump each other?
5.6 The noise sound likes Water flow inside the refrigerator ,in fact ,it is normal, which is
caused both when refrigerator start and shut-down; in addition, frost-
dissolving
causes this sound, too, which is a normal phenomenon.
5.7 There will be a cracking sound in the cabinet ,when the cabinet or cabinet accessory
contracting or expanding, this sound will be made, which is normal.
5.8 The motor operat ion sound in the compressor is appears to be louder at night or
begin starting. which is a normal phenomenon; also the uneven placing would lead to
too much running noise.
There is a peculiar
smell in the units
6.1 Is the food with special smell sealed tight?
6.2 Does it have long time storing food or degenerated food?
6.3 Whether the internal cabinet needs cleaning.
the forefront or the
middle cabinet heats
7.1 As fridge Anti-condensation tube is placed here and caused the above phenomenon,
which is normal.
Refrigerator’s two
sides or the back heat
8.1 As condensation tube is placed here and caused the above phenomenon, which is
normal.
the cabinet surface
condensation 9.1 Air humidity is too large.
◆The solution for the common problem.
1.Cooling is not enough good
(Many reasons might cause that cooling not enough good, as blow :)
Reason Analysis Solut ions
1) Leakage of Gas
If some gas leaked unit will work not well.
Phenomenon of failure:
a. lower pressure of liquid cycle system
b. high temperature of copper tube of
discharging gas, hand feels very hot.
C. much noise, sounds like “ZZZZZ”, comes
from outlet of capillary.
d. the temperature fell down very slowly.
First find out the point of leaking on
tube, and then sealed it, vacuuming
it, finally recharge with Gas.
Note:
If you find oil on somewhere, it is
possible that leakage point is there.
2)The quantity of Gas is If too much Gas was charged into the cycle First stop unit for several minutes,

too much system, the extra gas will occupy some space
of evaporator, so that the area of heat
exchange becomes less, unit will work not well.
Phenomenon of failure:
a, higher pressure of liquid cycle system than
norm.
b, higher temperature of condenser.
c, larger electric current of compressor
d, there maybe ice on the suction tube.
e, when gas is too much, some gas liquid might
goes back into compressor, compressor will be
damaged by liquid.
and then open charging tube,
discharge all of gas. Change a new
filter, and then recharge gas, finally
sealed the system.
3) There is air in the
liquid cycle system
The air in system will cause lower efficiency of
cooling.
Phenomenon of failure:
a, higher pressure of liquid cycle system than
norm, but the pressure is not over the limit.
b, higher temperature of discharging tube.
C, much noise
First stop unit for several minutes,
and then open charging tube,
discharge all of gas. Change a new
filter, and then recharge gas, finally
sealed the system.
4)Low working
efficiency of
compressor
Gener
al when a compressor works for many
years, some parts of compressor were wear, so
that compressor discharge less gas out, unit
does not work strongly.
Phenomenon of failure:
a, lower pressure of discharging, check the
pressure of system with pressure meter to see
if it is normal.
b, higher temperature of compressor surface.
C, cut off the discharging tube, to see if you can
block the gas coming out of the tube when
compressor is working.
Change a new compressor.
5
) There is something
that blocked the liquid
cycle system
Some t ime there is something blocked the
filter of liquid cycle system, so that unit is not
cold.
Phenomenon of failure:
a, lower pressure of discharging
b, lower temperature of discharging.
Change a new filter
2.NO COOL
(Popular failure reasons are below):
Reason analysis Solutions:
1) Leakage of gas
Phenomenon of failure:
a, leaking fast
b, leaking slowly
c, no voice of liquid flowing
d, cut off charging tube, no gas goes
out.
First find out the point of leaking on tube, and
then sealed it, vacuuming it, finally recharge
with gas.
Note：
If you find oil on somewhere, it is possible that
leakage point is there.

2)There is some thing
that blocked the liquid
cycle system
A,Ice blocking
Sometime because unknown reason
water comes into liquid cycle
system, the capillary will be blocked
by water after unit runs for period of
time.
Phenomenon of failure:
The unit works well in the inception,
after period of time the ice appears
in the capillary and becomes more
and more, till blocks the hole of
capillary completely. In the moment
you can fi
nd the ice on the
evaporator defrosts. The noise of
liquid flow disappears. The pressure
of absorbing becomes negative.
The phenomenon above will appear
again and again.
The way to check ice blocking:
Warm the capillary with a hot towel,
after a while the ice in the capillary
melt, you can hear a sound of gas
flow comes from the capillary
abruptly. The pressure of absorbing
becomes higher. It is Ice blocking.
First stop unit for several minutes, and then
open charging tube, discharge all of gas. Blow
the cycle system with gas of nitrogen, and then
recharge Gas, finally sealed the system.
B, there is offal block the capillary
Phenomenon of failure:
If the capillary is blocked by
something such as offal etc., the
sound of liquid flow disappears.
The ice on the evaporator defrosts
The pressure of absorbing becomes
negative.
Higher temperature of discharging
tube
The way to check offal blocking:
If you warm capillary with the way of
checking ice blocking, there is no
change. It must be offal blocking.
First stop unit for several minutes, and then
open charging tube, discharge all of gas. Blow
the cycle system with gas of nitrogen. Change
a new capillary and filter, and then recharge
Gas, finally sealed the system.
COMPRESSOR NEVER STOPS：
Reason Solutions
1) The sett ing temperature is not reasonable. Readjust the temperature setting.
2) the sensor is bad. Replace the sensor.
3) Seal of door is damaged. Replace the gasket
4) Too much food in the refrigerator Please put the food properly.
5) Wind door is broken. Replace wind door.

6) Fan motor is broken. Replace fan motor
■ Note:
●Before doing these operations above, disconnect the main power supply. Failure to do so could result in
electrical shock or personal injury.
●In case of any detailed technical information please check with the technical specifications.