Troubleshooting
- 107 -
C. Other failures
Failure
Method of correction
Main control board
PCB1 not operating
Check for molten FU fuse;
Check for normal DC12V, DC12V output on main control board
7812-3 pin, and DC12V input on wire controller;
Check for normal DC5V, DC5V output at main control board 7805-3
pin, and DC5V on wire controller RG1-3;
Check crystal circuit on main control board and for normal voltage at
crystal oscillator pins of chips 1 and 2;
Check for normal resetting circuit 7042 on main control board
Remote control
failure
Check for normal remote control receiver;
Check for normal remote control transmitter;
Check for normal remote controller
Remote controller
failure
Check for normal 3V batteries;
Check crystal oscillator circuit;
Check for normal transmitter;
Check for displaced or bad contact in conducting rubber
No cooling function
Check for normal temperature sensor RT1;
Check for normal DC12V, DC5V power supply;
Check for reliable connection of output ports of compressor, ID/OD
fans;
Check for main control board damage
No heating function
Check for normal temperature sensor RT1;
Check for normal DC12V, DC5V power supply;
Check for reliable output port connection of compressor, reversing
valve, ID fans and OD fans;
Check for main control board damage
Reversing valve
failure
Check for intact connection of outdoor unit wiring terminals;
‘19’ pin output on main control board MCU chip shall be high level;
relay RL1 shall close by suction;
Check for intact reversing valve
Indoor fan failure
Check for intact connection of indoor unit wiring terminal and damage
of main control board;
Summary of Contents for -B
Page 38: ...Main technical parameters 36 3 Value in is nominal value for auxiliary electric heating...
Page 43: ...Circuit diagrams 41 Chapter V Circuit diagrams I Circuit diagrams...
Page 44: ...Circuit diagrams 42...
Page 45: ...Circuit diagrams 43...
Page 46: ...Circuit diagrams 44...
Page 47: ...Circuit diagrams 45...
Page 48: ...Circuit diagrams 46...
Page 49: ...Circuit diagrams 47...
Page 50: ...Circuit diagrams 48...
Page 51: ...Circuit diagrams 49...
Page 52: ...Circuit diagrams 50...
Page 53: ...Circuit diagrams 51...
Page 54: ...Circuit diagrams 52...
Page 55: ...Circuit diagrams 53...
Page 56: ...Circuit diagrams 54...
