Mitsubishi Electric PUHY-RP200 Service Handbook page 218

[ IX Troubleshooting ]
In the case of MA remote controller
2. Phenomena
When the remote controller operation SW is turned on, the operation status briefly appears on the display, then it goes off,
and the display lights out immediately, and the unit stops.
(1) Cause
1) The power for the M-NET transmission line is not supplied from the outdoor unit.
2) Short circuit of the transmission line.
3) Incorrect wiring of the M-NETtransmission line on the outdoorunit.
ŒDisconnected wire for the MA remote controller or disconnected line to the terminal block.
ŒThe indoor transmission line is connected incorrectly to the transmission terminal block for centralized controller (TB7).
ŒThe male power supply connectors on the multiple outdoor units are connected to the female power supply switch connector
(CN40).
In the system to which the power supply unit for transmission lines is connected, the male power supply connector is connect-
ed to the female power supply switch connector (CN40) on the outdoor unit.
4) Disconnected M-NET transmission line on the indoor unit side.
5) Disconnected wire between the terminal block for M-NET line (TB5) of the indoor unit and the indoor unit board (CN2M) or
disconnected connector.
(2) Check method and remedy
1) When 2) and 3) above apply, check code 7102 will be displayed on the self-diagnosis LED.
Same symptom for all units in a
system with one outdoor unit?
Check the
self-diagnosis LED
Is the error code 7102
displayed?
Check 1).
See Section IX [4] -7- (2) Troubleshooting transmission power circuit of outdoor unit for how to check the items in Section 1 in the
flowchart above.(page 243)
HWE10010
NO
YES
YES
Check for
2) and 3).
NO
Check 4).
Correct
the error.
Correct the error.
- 209 -
Measure voltages of the
terminal block for transmission
line (TB5) on the indoor unit.
NO
17 - 30V?
YES
Check 5).
YES
Error found?
NO
Indoor unit board or
MA remote controller failure
GB