Daikin GYEQ20AN, Руководство по обслуживанию

Страница: 177 / 245

SiAUY361411EA Flow Charts for Troubleshooting
Troubleshooting 166
42
Inter-Unit Communication Failure
Error
code
U3
Description
of the failure
Sub-code 0: Unable to communicate between DCBL circuit boards for 20 seconds or longer
Sub-code 1: Unable to communicate between sub circuit boards for 20 seconds or longer
Sub-code 2: Abnormal sub circuit board ROM
Possible
causes
of the failure
Power supply failure; harness failure; main circuit board failure; power supply circuit board failure;
DCBL circuit board failure; sub circuit board failure
Flow chart
YES
Check Power Supply Harness.
Change Power Supply
Circuit Board.
Change DCBL Circuit Board.
Are the harness connections
of the main circuit board's CN21 and
the DCBL main circuit board's CN210
(including high power CN211)
operating normally?
YES
Is DCBL Circuit Board
Powered ON?
(Is LED10 Flashing?)
NO
Check Input/Output Voltage Of
Outdoor/Indoor Unit Breaker.
NO
Is Supply Voltage For Power
Supply Circuit Board's CN104 And
DCBL Circuit Board's CN201
Non-Defective?
YES
Correct Harness Connections.
NO
NO
Change DCBL Circuit Board.
Change Main Circuit Board.
Is Supply Voltage Normal?
YES
025910-01EN02
Sub-Code 0
YES
Check Power Supply Harness.
Change Power Supply
Circuit Board.
Change Sub-Circuit Board.
Change Sub-Circuit Board.
Is Harness For Connecting
Main Circuit Board's CN22 And
Sub-Board's CN319
Non-Defective?
YES
Is Sub-Circuit Board
Powered ON?
(Is LED Flashing?)
NO
Is Supply Voltage For Power
Supply Circuit Board's CN106 And
Sub-Circuit Board's CN202
Non-Defective?
YES
Change Harness Connections.
NO
NO
Change Sub-Circuit Board.
Change Main Circuit Board.
Sub-Code 1
Sub-Code 2