Mitsubishi Electric PUMY-P250YBM Technical & Service Manual page 80

Check code
6607
(A7)
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Procedure 1:
Turn the power OFF of indoor/outdoor unit, Fresh
Master, Lossnay and remote controller simultaneously
for 2 minutes or more, 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 tolerance or not.
It is not exceeding the tolerance.
Check whether the correct kind of
transmission line is used or not.
Continue to the next page.
OCH760
Diagnosis
Yes
Yes
Yes
Yes
No ACK error
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.
There is no abnormality on the AC unit.
It might be caused by an external noise, so check the
No
transmission line to remove the factor(s).
Set the address properly, then perform the
No
procedure 1.
Connect the transmission line properly,
No
then perform the procedure 1.
Correct it within the tolerance, then perform
No
the procedure 1.
80
Chart 3 of 4
Remedy