Samsung AM072/096/120/144FXVAFH, Service Manual

Page: 128 / 295

Troubleshooting
Samsung Electronics 4-31
Communication Error between Indoor and Outdoor Units after Tracking
(cont.)
غ
AM038/048/055KXWD
✳✳
1. How to check
Press the reset key (K3) of the outdoor unit PCB and
check the display module.
Is the voltage between the 2 cables a square
wave with DC±0.7V or more as shown in the image
below?
Is there no indoor unit response at all from the
display module during the tracking?
Remove the communication cable that connects the
outdoor unit to the indoor unit, and measure the 2
outdoor unit cables with a scope.
Connect the communication cable again to connect the outdoor
unit to the indoor unit.
Remove all the communication connectors on the PCB of the
indoor unit, and connect them one by one to find the indoor unit
which interferes with the communication to check and change the
indoor unit PCB.
After two minutes, find the indoor unit which displays the
communication error and check if the PCB address settings are
overlapped. (Communication error occurs if the indoor unit
addresses are overlapped.)
- In this case, the communication error will occur in every indoor
unit (2 or more units) with the address incorrectly set.
Check the communication cable and the
connector for the outdoor unit PCB, and
change the PCB.
0.7V
0.7V
Good
Defective
If there is no peculiarity in the address, check the
communication cable and change the indoor unit PCB.
Yes
No
No
Yes
Essential Requirements before Changing PCB in
Case of Communication Error : Refer to 63 page.
Yes
Outdoor unit display
Indoorunit display
Duct, Cassette (1/2 Way),Console, Celing Cassette (4/Mini4 Way) Wall-mounted (NeoForte)
Operation Defrost Timer Fan Filter/MPI Operation Defrost Timer Filter 18
℃
21
℃
Timer 24 ℃ 27 ℃
× × ◑ ◑
×
× ◑ ◑ × × × ◑ ◑ ×
※ ● : ON ◑ : Flash × : OFF
Judgment Method ∙ Outdoor unit is unable to communicate for two minutes during operation. (no reception of relocation)
Cause of problem ∙ Communication error between indoor and outdoor units and setup error of indoor unit installation quantity setup switch..