Samsung KFH28, KFH28PV20K-KLM Troubleshooting

5. Troubleshooting

Troubleshooting procedures

1st	• Items to be checked first.
2nd	• Check the corrective actions in the case of occurrence of self-diagnosis mode.
3rd	• When the trouble is not related to the 1st or 2nd items above, check the troubled area in detail in accordance
	with the fault analysis method by symptom.

5-1 Items to be checked first

1)Is the supply voltage appropriate ? Report to 3-10 Page-Electric

2)Is the connecting wire between the indoor unit and outdoor unit appropriate ?

The indoor unit and outdoor unit should be connected with each other by 8 cables. (sensor wire included) Be sure to check whether the cables for the indoor unit and outdoor unit are securely connected by the same terminal number.

3)When any claim occurs according to the contents of the table below, it is not related to the trouble of the air conditioner at all.

No	Operation of air conditioner	Description
1	• In a COOL operation mode, the compressor does not operate at a	• In happens after a delay of 3 minutes when the compressor is reoperated.
	room temperature higher than the setting temperature that the	The same phenomenon occurs when a power is on.
	compressor should operate.	• As a phenomenon that the compressor is reoperated after a delay of 3 minutes, the
	• In a HEAT operation mode, the compressor does not operate at a	indoor fan is adjusted automatically with reference to a temperature of the air blew
	room temperature lower than the setting temperature that the
	compressor and indoor fan should operate.
2	The fan speed cannot be controlled during AUTO, DRY, TURBO, or	• The fan speed is automatically set at the micom during AUTO, DRY, TURBO or
	MILD operation.	MILD operation.
3	The temperature is not set during AUTO, FAN, TURBO or MILD	• The desired temperature is automatically set at the micom during AUTO, TURBO or
	operation.	MILD operation.
		• The fan operation circulates the room air without temperature control
4	Compressor stops operation intermittently in DRY mode.	Compressor operation is controlled automatically in DRY mode depending on rthe
		room temperature.
5	Compressor of the outdoor unit is operating although it is turned off in	When the unit is turned off while de-ice is activated, the compressor continues
	a HEAT mode.	operation for up to 9 minutes 40 sec (maximum) until the deice is completed.
6	Timer Display only of the indoor unit lights up and the air conditioner	Timer is being activated and the unit is in ready mode.
	does not operate.	The unit operates normally if the timer operation is cancelled.
7	The compressor and indoor fan stop intermittently in HEAT mode.	The compressor and indoor fan stop intermittently if room tempreature exceeds
		a setting temperature in order to protect the compressor from overheated air in a
		HEAT mode.
8	Indoor fan and outdoor fan stop operation intermittently in a HEAT	The compressor operates in a reverse cycle to remove exterior ice in a HEAT
	mode	mode, and indoor fan and outdoor fan do not operate intermittently for within 20% of
		the total heater operation

5-2	Self-diagnosis and Corrective Actions
NO		Control panel	Temperature	Cause	Corrective actions
		lamp condition	display
1		Check display	E1	• Room temperature sensor short	• Replace the room temperature sensor.
		on blinking(1Hz)		• Room temperature sensor open	• Check the main PCB pattern and components for short or open.
			E2	• Panel shutter binding at the time of	• Remove cause of binding.
2		Check display		mechanical assembly.	• Replace the panel shutter motor.
		on blinking(1Hz)		• Defective panel shutter motor.	• Replace the sensor PCB.
				• Defective sensor PCB.
3		Check display	E5	• Indoor evaporator sensor open or shor t	• Check the evaporator sensor wire
					• Replace the evaporator sensor wire
		on blinking(1Hz)
					• Check the main PCB pattern and componets for short or open
4		Check display	E6	• Outdoor condensor sensor open or short	• Check the condensor sensor wire
					• Replace the evaporator sensor wire
		on blinking(1Hz)
					• Check the main PCB pattern and componets for short or open

5-1

5-3 Fault Analysis by Symptom

5-3-1 No Power (No display)

1) Checkpoints

1Is the voltage of the power source normal ?

2Is the power line in good contact ?

3Check the power fuse (F701, F702) and PCB fuse (F101) for open.

4 Are the primary and secondary sides of the power-trans in good contact with the connector?

5Is the output voltage of IC08 (KA7812)normal ? (DC 11.5V~DC 12.5V)

6Is the output voltage of IC09 (KA7805)normal ? (DC 4.5V~DC 5.5V)

2)Checking Procedures <After checking the checkpoints of clause 1)>

Turn off the power, and then turn it on in five seconds.

The VF-Display turned on, and the panel shutter down when pressing the ON/OFF Button ?

N

Is the voltage of the power trans secondary side(CN11) normal?

Red-Red	AC 4V-5V
Blue-Black	AC14V-17V
Blue-White	AC16V-19V

Y

Is the output voltage of IC08, and IC09 normal? (IC08=12V, RIC09=5V)

Y

Y	Then it is normal operation

N

Check and replace the power trans.

	N	• Remove the shorted parts of
		the power terminal.

•Replace defective parts. (D101, D102, IC08, IC09)

Is the output wave at the micom(IC1) pin No. 33~37

N

Check and replace the micom(IC01).

a square wave ?

Y

N

Is the output wave at IC05 pin No 11~18, and IC06 pin No 11~18

Check and replace the IC05, and IC06.

a square wave?

Harness check and replace

Y

Is the harness between the main PCB and power PCB well

N

Reassemble or replace the

connected ?

harness after checking it.

Y

VF display or main PCB defective.

5-2

Troubleshooting

5-3-2 When the Indoor Fan Motor does not Operate.

1) Checkpoints

1Is the voltage of the power source normal?

2Is the indoor fan connector (CN71) in good contact?

3Is the starting condenser of the fan motor in good contact with the terminal?

4Is the resistance at both ends of the relay (RY71 ~ RY74) coil approximately 720Ω?

2)Checking Procedures <After checking the checkpoints of clause 1)>

Turn off the power, and then turn it on in five seconds.

Operate the ON/OFF button, and operation mode key, and place

Go to the item of "No power

it in the "FAN" position.

parts" (Refer to page 5-2)

Y

Does the airflow volume of the indoor fan motor change when

Then the indoor fan motor is normal.

converting into high, medium, and low by the FAN speed key ?

N

Y

Do the RY71 (low), RY72 (medium), and RY73 (high) operate when

Then the relay is normal.

converting into high, medium, and low by the Fan speed key ?

N

N

Check the

Is the resistance at both ends of the relay (RY71~73)

Then relpace the relay when the

resistance after

approximately 720Ω ?

resistance is 0Ω or ∞

turning off the

Y

N

power.

Is it "HIGH" when checking the output wave for each airflow

Then check and replace the

at the micom(IC01) pin No. 54, 55, and 56 ?

micom(IC01)

Y

Is it low when checking

Is the voltage at both ends of the relay for each airflow at the

N

the output wave for each airflow

Then check and

time of selecting the fan speed(high/medium/low) DC12V ?

at the IC02 pin No.16, IC07 pin

replace the IC02,

No. 10 and 11?

IC07

Y

Y

N

Is the voltage at both ends of the indoor fan motor

Then check the wiring harness

220VAC?

for open.

Check and replace the indoor fan motor.

5-3