Troubleshooting44Samsung ElectronicsBranch3-7 Communication error (1 minute) between Main and Sub Micoms of an Outdoor unit or amongOutdoor Units (Error Code : E203)1. Inspection Method : Check the Main PCB MCU quantity setting switch of the outdoor unit and check the installed MCU quantitymatches.Check whether each MCU PCB address switch was duplicated.To use, reset by pressing the K3 button of the outdoor unit after the reset is completed, or reset after turning offthe power and then turn it on again.• Example of MCU quantity setting errorex) PCB MCU setting quantity of outdoor unit = 2 / MCU installed Quantity = 3• Example of MCU address setting errorex) Two among three of MCU address was set to 0Outdoor unitdisplayIndoorunitdisplayDuct, Cassette (1/2 Way),Console, Celing Cassette (4/Mini4 Way) Wall-mounted (NeoForte)Operation Defrost Timer Fan Filter/MPI Operation Defrost Timer Filter Operation Timer Turbo 24℃ 27℃× × ◑ ◑ × × ◑ ◑ × × × ◑ ◑ ×※ ●: ON ◑: Flash ×: OFFJudgmentMethod• Occurs when the quantity of MCU is incorrectly set by the outdoor unit.• Occurs when same addresses are found when two or more MCU are connected.• Occurs when there is no HR changer in HR application.• Occurs when there is HR changer or MCU in HP application .Special Cause • Outdoor unit MCU setup and same address errors when connecting two or more MCUs .
