Mitsubishi Electric PUMY-P250YBM Technical & Service Manual page 81

Check code
6607
(A7)
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Continued from the previous page.
Is the correct kind of transmission
line used?
Is it operating in multi refrigerant
system?
When operating in a multi refrigerant system (2 or
more outdoor units), check if any of the indoor unit
stores non-existing address information.
Is the address information correct?
Check the wiring.
Is the wiring on the circuit board
connected properly?
Replace the controller board which the
displayed address/attribute belongs to.
Does it operate normally?
OCH760
Diagnosis
Yes
Yes
Yes
Yes
Yes
No ACK error
Apply the correct kind of transmission line,
No
then perform the procedure 1.
When operating in a single refrigerant
system (single indoor unit), the controller of
No
the displayed address/attribute is defective.
Delete the unnecessary address using
a manual setting function on the remote
No
controller.
(Only for operating in a system with the
Fresh Master/Lossnay is connected, or in a
multi refrigerant system with group setting
is set).
Connect the wiring properly.
No
Defective outdoor controller board (repeater circuit)
on the outdoor unit is suspected.
No
Replace the outdoor controller board one by one,
then check for normal operation.
81
Chart 4 of 4
Remedy
Complete.