Product specifications

Samsung Electronics 4-26
4-6 PCB Inspection Method
4-6-1 Pre-inspection Notices
4-6-2 Inspection Procedure
4-6-3 Indoor Detailed Inspection Procedure
1. Turn off the breaker, AC power source, before disassembling the unit because of electrical hazard.
2. Confirm the complete discharge of capacitor C102, C702, C703, C704, C705, C706, C707 on the INVERTER PCB when you touch
the PCB. Especially dischargeing speed of C702-C707 is very slow because of little load in stand-by condition. To confirm
the voltae of 702-C707, measure the DC link voltage at the IGBT module pins near C701 at which applying voltage (450-510Vdc) is
marked. To confirm discharging of C102, measure the voltage of non mounted C103 solder hole or check if all LEDs are off.
3. Don’t touch the metal body of electrolytic capacitor for avoiding electrical shock before confirming discharge.
4. To discharging the capacitor use power resistor of about 1 Kohm 10W. Soldering tool(non electronic temperature control type)
can be used as a discharging resistor.
5. Don’t pull the lead wire but hold the whole housing to disconnect or connect a housing from or to the PCB.
1. Check the connection of each housing to the connector first and the peeling of PCB copper pattern.
2. The PCB is composed of the 3 part in the indoor unit.
● INDOOR Main PCB part : Indoor unit control, MICOM and surrounding circuit, relay, fan motor driving circuit, sensor reading
circuit, buzzer driving circuit and DC power supplying circuit.
● Display PCB part : LED lamps, Switch,Remocon module.
● INDOOR EMI PCB part : Line filter, Noise Capacitor and Varistor
3. The PCB is composed of the 3 part in the outdoor unit.
● EMI PCB part : Line filter for electrical noise, Varistors for surge and Fuses.
● MAIN PCB part : Refrigeration cycle controller with MICOM
● INVERTER PCB part : Compressor driving inverter and BLDC fan controller
No Procedure Inspection Method Cause
1
Open the electronic
component box and
check the PCB fuse
Turn off the power
1) Is the Fuse F701 on the EMI PCB blown?
2) Is the Fuse F702 on the MAIM PCB blown?
•Over current
•Indoor fan motor short
•PCB AC Part pattern short
2
Check the LEDs for
DC power and
communication condition
Turn off the power
1) Is RED LED blinking?
his led means micom is running normally
2) Is GREEN LED blinking?
This means communication between
Indoor and Outdoor unit is on
3) Is YELLOW LED blinking?
This means communication between
Indoor and wired remote controller is on
It may take one minute to start
communication
•Communication ciucuit trouble
•Communication wire
connection trouble
•Wrong connection for
power supply wire of
remote controller
3
Check the DIP and rotary
switch on the PCB
1) Is the setting of each switch proper?
•Wrong setting of switch
4
Check the DC voltage 1) Is the voltage of CN32 pin #1-#2 12V?
2) Is the voltage of C109 V?
•SMPS on MAIN PBA trouble
•Load short
5
FAN operation checking
Press the ON/OFF button.
1. FAN Speed[HIGH]
2. FAN mode
1) Is the FAN motor running?
2) Is the connection of CN73 normal?
•Controller trouble inside of
the fan motor
•Connector trouble of CN73