Mitsubishi Electric PQHY-P72ZLMU-A Service Handbook page 317

[ IX Troubleshooting ]
In case of ME remote controller
1. Phenomena
Even if the operation button on the remote controller is pressed, the display remains unlit and the unit does not start running.
(Power indicator does not appear on the screen.)
(1) Cause
1) The power for the M-NET transmission line is not supplied from the indoor unit.
2) Short circuit of the transmission line.
3) Incorrect wiring of the M-NET transmission line on the heat source unit.
Disconnected wire for the MA remote controller or disconnected line to the terminal block.
The indoor transmission line is connected incorrectly to the transmission terminal block for centralized controller (TB7).
4) Disconnected transmission line on the remote controller.
5) Remote controller failure
6) Heat source unit failure (Refer to IX [8] Troubleshooting Using the Heat source Unit LED Error Display.)
(2) Check method and remedy
1) Check voltage of the transmission terminal block for of the ME remote controller.
If voltage between is 17V and 30V
When voltage is 17V or less
2) When 2) and 3) above apply, check code 7102 will be displayed on the self-diagnosis LED on the heat source unit.
HWE15150
ME remote controller failure
Refer to IX [4] -7- (2) "Troubleshooting transmission power curcuit of heat source unit".
- 308 -
GB