Sinclair SDV5 Series Service Manual page 45

2 Troubleshooting
2.1 Warning
Warning
 All electrical work must be carried out by competent and suitably qualified, certified and accredited professionals
and in accordance with all applicable legislation (all national, local and other laws, standards, codes, rules,
regulations and other legislation that apply in a given situation).
 Power-off the outdoor units before connecting or disconnecting any connections or wiring, otherwise electric
shock (which can cause physical injury or death) may occur or damage to components may occur.
2.2 C0: Communication fault between main board and communicate converter board (Only for 100/120
model)
2.2.1 Digital display output
C0
2.2.2 Description
 Communication fault between main board and communicate converter board.
 The system stops running.
 Error code is displayed on the outdoor unit PCB.
2.2.3 Trigger / recover condition
 Trigger condition: Communicate converter board and ODU main control board cannot communicate.
 Recover condition: Communication go back to normal.
 Reset method: Resume automatically.
2.2.4 Possible causes
 Interference from high voltage wires or other sources of electromagnetic radiation.
 Communicate converter board is damage.
 Communicate wire port is loose or connecter surface is corrosive, or water drop lead to poor contact.
 Communicate wire break or poor contact for reasons (such as rat beat, or bond and connection).
2.2.5 Procedure
Dismantle the connect wire between communicate converter
board and ODU main board, and then test the T and R port
voltage of the ODU main board to confirm whether it's 5V
Dismantle the T and R port between communicate converter
board and ODU main board, and then test the TR port voltage
of the communicate converter board to confirm whether it's 5V
Confirm the communication port is loose or not, exclude
communication problem, confirm there's no outer interference
44
C0
Yes
Yes
Outdoor unit main
No
board fault
Communicate
No
converter board
fault