LG Gr P227 Ytqa Service Manual

2-12. Function of Trouble Diagnosis(88-LED)
1. Failure diagnosis function is function to facilitate service when nonconforming matters affecting performance of product
during use of product.
2. In occurrence of failure, pressing the function adjustment button does not perform function and only alarm sound (“Ding~”) rings.
3. If nonconforming matters occurred are released during display of failure code, MICOM returns to the original state (Reset).
4. Failure code is displayed on the display part of...

MICOM FUNCTION
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2-13. Function of Trouble Diagnosis(Bar-LED)
1. Function of trouble diagnosis is to make the repair  service easy when the refrigerator is out of order during service.
2. The function control button does not work but the recognition sound is heard when the refrigerator is out of order.
3. It returns to normal conditions when trouble code led is off. (reset)
4. Trouble code is indicated by the freezing temperature indicator led in the refrigerator display. All leds except trouble...

Function of Trouble Diagnosis(88LED)
2-14. Test Function
1. The purpose of test function is to check function of the PWB and product and to search for the failure part at the failure
status.
2. Test button is placed on the main PCB of refrigerator (test switch), and the test mode will be finished after maximum 2
hours irrespective of test mode and then is reset to the normal status.
3. Function adjustment button is not perceived during performance of test mode but only warning sounds ring.
4. In...

- 24 - Function of Trouble Diagnosis(BAR LED)
2-15. Test Function
1. The purpose of test function is to check function of the PWB and product and to search for the failure part at the failure
status.
2. Test button is placed on the main PCB of refrigerator (test switch), and the test mode will be finished after maximum 2
hours irrespective of test mode and then is reset to the normal status.
3. Function adjustment button is not perceived during performance of test mode but only warning sounds ring.
4. In...

* LED check function- When freezer and refrigerator temperature control buttons are pressed for more than 1 second at the
same time, all LEDS on the display are on. And it returns to the normal conditions when the buttons are released. 
* Check of freezer fan rpm variation- Freezer fan speed changes from high speed to standard speed and vice versa for 30
seconds whenever freezer and refrigerator temperature control buttons are pressed at the same time for more than 1
second when freezer fan is in...

1. Explanation for PWB circuit
1-1. Power circuit
Power circuit consists of SMPS (SWITCHING MODE POWER SUPPLY) power. The SMPS consist of the rectifying part
(BD1, CE1) converting AC voltage to DC voltage, the switching part (IC2) switching the converted DC voltage, transformer
transferring energy of the primary side of the switching terminal to the secondary side and the feedback part (IC3, IC4)
transferring it to the primary side. 
Caution : Since high voltage (DC310V) is maintained at the power...

EXPLATION FOR MICOM CIRCUIT 
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1-2. Oscillation circuit
Oscillation circuit is a circuit with the purpose of generating basic time for clock occurrence for synchronization and time
calculation in relation with information transmission/reception of inside elements of IC1 (MICOM). The OSC1 must always
use rated parts since if SPEC is changed, time calculated at the IC1 may be changed or no operation is done.
1-3. Reset circuit
The reset circuit is circuit allowing various parts such as RAM inside of MICOM (IC1) to initialize and the...

1-4. Load/dispenser operation, buzzer driving, door opening circuit
1. LOAD DRIVING CIRCUIT
✽InEven if opening the door of freezing room or cold storage room during operation of fan motor at the freezing room, this
circuit does not stop and operates at the standard RPM. In addition, if doors of freezing room or cold storage room, the
fan motor normally operates at the RPM previously operated.
✽(A), (B), (C) and (D) of door switch for the freezing room or cold storage room are connected to the door open...

EXPLATION FOR MICOM CIRCUIT 
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