Samsung AM072FXVAFH series Service Manual page 122

Troubleshooting
4-4-3- Communication Error between Indoor and Outdoor Units during Tracking
Outdoor unit display
Indoorunit display
Judgment Method
∙ Communication error between indoor and outdoor units.
Cause of problem ∙ Refer to the judgment method below..
1. How to check
Indoor Unit Installation Quantity Setup Switch of
Outdoor Unit Compare and check the set value
and the actual number of indoor units installed.
actual installed indoor units and the set value for
the installation quantity setup
Press the reset key (K3) of the outdoor PCB, and
check the display module to check for the quantity
of indoor units that respond to the tracking.
the indoor response on the display
Remove the communication cable which connects
the outdoor unit to the indoor unit, and measure
the 2 cables of the outdoor unit with a scope.
Is the voltage between
the 2 cables a square wave with DC±0.7V or more
as shown in the image below?
Check the communication cable
which connects the outdoor unit to the indoor unit.
If there is no peculiarity, then connect the indoor units one
by one to find the indoor unit that is interfering with the
communication for inspection and change the indoor unit PCB.
0.7V
0.7V
4-26
Duct, Cassette (1/2 Way),Console, Celing
Operation Defrost Timer Fan
× × ◑ ◑
※ ● : ON ◑ : Flash × : OFF
Are the number of
switch the same?
Yes
Is there no sign of
during tracking?
Yes
Yes
Good
Cassette (4/Mini4 Way)
Filter/MPI Operation Defrost Timer
× ◑ ◑
×
No
Correctly set the indoor unit installation quantity
setup switch of the outdoor unit, and press the
reset key (K3) of the outdoor PCB to re-execute
No
After 2 minutes, find the indoor unit which displays
the communication error for the indoor units, and
check for overlaps in the PCB address setup.
(If the indoor unit addresses are overlapped,
then a communication error will occur).
- In this case, a communication error will occur
in every indoor unit (two or more units) with
Change the indoor unit PCB after checking
the communication cable when there is
No
no peculiarity with the address.
Check the communication cable and the
connector of the outdoor unit PCB,
and change the PCB.
* Essential Requirements before Changing PCB
in Case of Communication Error: Refer to p.50
Defective
Wall-mounted (NeoForte)
Filter Operation Timer Turbo
× × ◑ ◑
tracking.
the address incorrectly set.
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