Fault Diagnosis By Symptom(Dvm Hr2 Series) - Samsung AVXC1H022 series Service Manual

9-5 Fault Diagnosis by Symptom(DVM HR2 Series)

I
: Communication error between the outdoor unit and MCU
Outdoor unit display
Indoor unit display
Judgment method
Causes
Is OK the connection between
the outdoor unit and communication
Press the reset(K3) outdoor unit PCB
and check the display part.
Is there any response of MCU or
indoor unit from the display part on tracking?
Remove the communication line from the out-
door unit to MCU, and measure 2 lines of
indoor unit side by use of scope.
After connecting the communication line connected
from the outdoor unit to MCU again, remove all commu-
nication connectors of MCU and outdoor unit. And then
connect it one by one to find a communication obstacle
and replace PCB after checking the communication line.
9-69
- Communication error between the outdoor unit and MCU
connector?
Yes
Yes
MCU address: Fb-FE
Yes
Yes
Is the voltage of
2 lines square wave of
DC ±0.7V?
Yes
No
Restart after connecting a
connector to PCB.
No
Check again the communication line con-
nected with MCU.
If there is no error after checking the
communication line, replace MCU PCB.
No
If there is no error after checking the
communication line and connector of out-
door PCB, replace MCU PCB.
Samsung Electronics