Mitsubishi Electric PUHY-HP72 Service Handbook page 205

[8-2 ME remote Controller Problems ]
3. Check method and remedy
Without using MELANS
Are all the units in the system
experiencing the same problem?
Check the address of
the outdoor unit.
51 - 100?
Check the centralized centralized
switch (SW5-1) on the outdoor unit.
ON?
Indoor unit control board failure
*1. When the outdoor unit address is set to 1 - 50, the address will be forcibly set to 100.
8
- chapter 8
NO
YES
*1
NO
A wrong address is
set to the outdoor unit.
YES
YES
Wrong switch setting
Change it from
ON to OFF.
NO
Correct
the error.
Check the address of the ME remote controller
on which "HO" is displayed.
NO
A wrong address is
Indoor unit + 100?
set to the ME
remote controller.
YES
Check the address of the
indoor unit to be coupled.
NO
ME remote controller
A wrong address is
- 100?
set to the indoor unit.
YES
Measure voltages of the terminal
block for M-NET transmission line
on the indoor unit.
Wrong wiring of the
NO
M-NET transmission
17 - 30V?
line of the indoor unit
YES
Check connection between indoor M-NET
transmission terminal block (TB5) and the
male connector (CN2M)
YES
Disconnected
Disconnected?
connector (CN2M)
NO
Indoor unit board or
remote controller failure
HWE18240_GB