Ho" And "Please Wait" Do Not Go Off The Screen - Mitsubishi Electric PUHY-P250YNW-A Service Handbook

[8-1 MA Remote Controller Problems ]
8-1-3

"HO" and "PLEASE WAIT" Do Not Go Off the Screen.

1. Phenomena
"HO" or "PLEASE WAIT" display on the remote controller does not disappear, and no operation is performed even if the button
is pressed. ("HO" or "PLEASE WAIT" display will normally turn off 5 minutes later after the power on.)
2. Cause
1) The power for the M-NET transmission line is not supplied from the outdoor unit. For details, refer to the following page(s).
[8-10-2 Troubleshooting Problems with Outdoor Unit Transmission Power Supply Circuit]
2) Short-circuited transmission line
3) Incorrect wiring of the M-NET transmission line on the outdoor 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).
The 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.
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.
6) Incorrect wiring for the MA remote controller
Short-circuited wire for the MA remote controller
Disconnected wire for the MA remote controller (No.2) and disconnected line to the terminal block.
Reversed daisy-chain connection between groups
Incorrect wiring for the MA remote controller to the terminal block for transmission line connection (TB5) on the indoor unit
The M-NET transmission line is connected incorrectly to the terminal block (TB13) for the MA remote controller.
7) The sub/main setting of the MA remote controller is set to sub.
8) 2 or more main MA remote controllers are connected.
9) Indoor unit board failure (MA remote controller communication circuit)
10) Remote controller failure
11) Outdoor unit failure (Refer to the following page(s).[8-13 Troubleshooting Problems Using the LED Status Indicators on the
Outdoor Unit])
12) The outdoor unit address is set to an address other than "indoor unit address plus 50."
13) The indoor unit address is set to a number 51 or highe
3. Check method and remedy
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?
Error found?
Check 1).
BS_08_C
NO
YES
YES
Check
2) and 3).
NO
Replace the M-NET remote
YES
controller with the MA
remote controller
NO
Check 4).
YES
Correct
the error.
Correct
the error.
Measure voltages of the
terminal block for transmission
line (TB5) on the indoor unit.
17 - 30V?
YES
Check for 5), 6), 12) and 13).
Error found?
NO
Indoor unit board or
MA remote controller failure
chapter 8 -
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