Troubleshooting By Symptoms; When The Outdoor Unit Power Is Not On - Initial Diagnosis : 1-Phase Products - Samsung AC071MN4PKH Service Manual

4-4. Troubleshooting by symptoms

4-4-1. When the indoor unit power is not ON – Initial Diagnosis : 1-phase products
1. Test items
1) Check the power connection of indoor/outdoor unit and check the power wire of Terminal Block.
2) Check the connection of the power wire between the Power PCB
3) Check the power supply parts. (Check after turning off the power of the Terminal Box!)
4) Check everything is normal after separating the fan motor connector and resetting the power.(Separate the connector after turning off the power of the
Terminal Box! When detaching and attaching the connector during power supply, the motor can be damaged.)
2. Check procedure
30 seconds after turning off the Main Power Switch
(Breaker or Power outlet), turn on the power.
Check the power to the indoor unit.
1. Is the voltage 220Vac between the wires?
(Example) L N
Check the connection of the
power wire between Power PCB and Main PCB DC.
1. Did applicable wire is connected
properly?
Check the
power supply parts.
(Switch off power to the
Terminal Box before inspection!)
1. Is there a fault with a fuse?(Short-Normal, Open-Fault)
2. When the Bridge Diode is measured with "+ / -"
(output voltage), does the voltage exceed 290Vdc?
3. Is 12V & 5V power supply is normal?
DC output can be confirmed by the
voltage at both ends of the Cap.
(12V : CE100,
5V : CE101)
Fan Motor
connector after separating
and resetting the power, check everything
is normal.(Separate the connector after turning off
the power of the Terminal Box! When detaching and
attaching the connector during power supply,
the motor can be damaged.)
If it is normal, replace
the Fan Motor.
Yes
Yes
Yes
Yes
Main PCB DC of indoor unit. (Check after turning off the power of the Terminal Box!)
Check the all power wire connection of indoor/outdoor unit.
1. Check the power of the Terminal Box,1-phase power phase.
(Check the connection error.) If the indoor unit AC voltage
of about 290V or more, no operation by the PCB protective
action.
2. Check the connection of Terminal Block power wire. Check
No
whether each wires were connected rightly.
(Refer to electrical schematics)
3. If the connection is made in the power wire (extension of the
power wire), make sure that it is securely connected.
4. Check the circuit breaker due to over-current, or leakage.
Check whether several units are connected to one breaker.
Check the power wire between Power PCB and Main PCB DC.
No
1. Make sure that the DC power cable is properly connected to
the connector (CN100).
After replacing the main PBA and resetting the power, check
everything is normal.
No
1. If the Fuse is defective, replace the Fuse or Power PCB.
2. If the Bridge Diode is defective, replace the Bridge Diode or
Power PCB.
3. If the 12V & 5V output is defective, replace the Main PCB.
Connect the power wire. (Switch off power to the Terminal Box!)
No
1. Connect the power wire.
2. Check whether the power of the outdoor unit is supplied by
powering on the Terminal Box.
4-25
Troubleshooting