MXZ-SM42NAMHZ Service Manual

92
OCH789
Check code
Abnormal points and detection methods Causes and checkpoints
If the transmission line shows "1" although the transmission processor
transmitted "0".
A transmitting data collision occurred because of a
wiring work or polarity change has performed while
the power is ON on either of the indoor/outdoor unit,
Fresh Master or Lossnay
Malfunction of transmitting circuit on transmission
processor
Noise interference on indoor/outdoor connectors
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis Remedy
6602
(A2)
Transmission processor hardware error
Yes
Yes
No
No
A wiring work was performed
while the power OFF.
Does it operate normally?
If the wiring work was performed while the
power ON, turn the power OFF of indoor/
outdoor unit, Fresh Master or Lossnay
simultaneously for 2 minutes or more, then
turn the power back ON.
Replace the indoor/outdoor controller board.
There is no abnormality on the AC unit.
It might be caused by an external noise, so
check the transmission line to remove the
factor(s).
Turn the power back ON.