Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 74

6607 (A7): No ACK error
Diagnosis of failure
Note:
• When the address of the outdoor unit is displayed as abnormal, the outdoor circuit board may be faulty. If the unit is
not restored after conducting the following procedure, check the outdoor circuit board.
Procedure 1:
Turn the power OFF of indoor/outdoor unit,
Fresh Master, Lossnay and remote controller
simultaneously for 10 minutes, then turn the
power back ON.
Is the abnormality replicated?
Check the address switch on the source of
abnormality.
Is it set properly?
Check the transmission line for disconnection
and looseness
(on the terminal board and connector).
The transmission line is connected
properly.
Check the transmission line whether it exceeds
the limits or not.
It exceeds the limits.
Check whether the correct transmission line is
used or not.
Continue to the next page.
OCH800A_74
No
Yes
No
Yes
No
Yes
Yes
No
No
Is the error code
<1302> High pressure
trouble displayed ?
Yes
Set the address properly, then perform the
procedure 1.
Connect the transmission line properly, then
perform the procedure 1.
Correct it within the limits, then perform the
procedure 1.
Chart 3 of 4
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).
Refer to the diagnosis of error code
<1302> High pressure trouble.