Display Fault; Failure Display - Nobu NBFS-48IDU Service Manual

7. Failure display

running
LED lamp(flicker lamp(flicker
times)
F1 1
F2 2
F3 3
F4 4
timer
Fault content
times)
light communication fault
The indoor ambient
light
temp. sensor fault
The coil pipe temp.
sensor of indoor unit
light
fault(include ：inlet,
middle, outlet)
light indoor fan fault
The reason of fault and solution
1、Check whether the connection of the outdoor
unit and indoor unit is one to one, otherwise
connect the L, N and communication line of
the indoor unit and outdoor unit one to one.
2、Measure whether the voltage between the zero
line and the communication line is 18V-30AC
half-wave signal, check whether the
communication circuit on the indoor and
outdoor electric control board has been
damaged, otherwise replace it.
3、Check whether the LED on the outdoor power
board has been on, otherwise replace the
electric control board.
4、Check whether the unit is abnormal caused by
the external interference, if it is, then find the
interfering source, and removes it.
1、Check whether the resistance of sensor is
normal, otherwise replace it.
2、Check whether the sensor wire is short circuit
or open circuit, and whether the plug is well
contacted, whether there is welding off or
rosin joint on the electric control board, repair
it if there is any above.
3、When the 1 and 2 are both normal, then the
components or integrated circuit is damaged,
the electric control board should be replaced.
1、Check whether the resistance of sensor is
normal, otherwise replace it.
2、Check whether the sensor wire is short circuit
or open circuit, and whether the plug is well
contacted, whether there is welding off or
rosin joint on the electric control board, repair
it if there is any above.
3、When the 1 and 2 are both normal, then the
components or integrated circuit is damaged,
the electric control board should be replaced.
1、 Check whether the contact of the plug of the
motor wire and socket is well, making sure
well contact.
2、Check whether the indoor motor has damaged,