Troubleshooting By Inferior Phenomena - Mitsubishi Electric PUHZ-HRP71VHA Service Manual

Error Code Abnormal point and detection method
M-NET NO RESPONSE
Abnormal if a message was transmitted
and there were reply (ACK) that message
was received, but response command
does not return. Transmitting side detects
abnormality every 30 seconds, 6 times
continuously.
Note) The address and attribute displayed
at remote controller indicate the con-
troller that did not reply (ACK).
A8
(6608)

10-5. TROUBLESHOOTING BY INFERIOR PHENOMENA

Phenomena
1. Remote controller display does not
work.
2. "PLEASE WAIT" display is remained
on the remote controller.
3. When pressing the remote controller
operation switch, the OPERATION
display is appeared but it will be
turned off soon.
Transmitting condition is
repeated fault because of
noise and the like.
Extension of transmission wire
voltage and signal is caused
by over-range transmission
wire.
• Maximum distance .... 200m
• Remote controller line (12m)
Extension of transmission wire
voltage and signal is caused
by type-unmatched transmis-
sion wire.
Type ....
With shield wire-
CVVS, CPEVS
With normal wire (no shield)-
VCTF, VCTFK, CVV
CVS, VVR, VVF, VCT
Diameter .... 1.25mm
Accidental malfunction of
abnormality-generated
controller
Factor
DC12V is not supplied to remote controller.
(Power supply display is not indicated on LCD.)
DC12~15V is supplied to remote controller, however,
no display is indicated.
• "PLEASE WAIT" is not displayed.
• "PLEASE WAIT" is displayed.
At longest 2 minutes after the power supply "PLEASE
WAIT" is displayed to start up.
Communication error between the remote controller
and indoor unit
Communication error between the indoor and outdoor
unit
Outdoor unit protection device connector is open.
After cancelling to select function from the remote
controller, the remote controller operation switch will
be not accepted for approx. 30 seconds.
39
Case
Check transmission waveform or noise on
transmission wire.
Turn off the power supply of outdoor unit
and indoor unit and FRESH MASTER or
LOSSNAY at the same time for 2 minutes or
more, and turn the power on again. If mal-
function was accidental, the unit returns to
normal. If the same abnormality generates
again, controller of displayed address and
attribute may be defective.
2 or more
Check LED2 on indoor controller board.
(1) When LED2 is lit.
Check the remote controller wiring for
breaking or contact failure.
(2) When LED2 is blinking.
Check short circuit of remote controller
wiring.
(3) When LED2 is not lit.
Refer to No.3 below.
Check the following.
• Failure of remote controller if "PLEASE
WAIT" is not displayed
• Refer to No.2 below if "PLEASE WAIT" is
displayed.
Normal operation
Self-diagnosis of remote controller
"PLEASE WAIT" is displayed for 6 min-
utes at most in case of indoor/outdoor
unit communication error. Check LED3 on
indoor controller board.
(1)When LED3 is not blinking.
Check indoor/outdoor connecting wire
for miswiring.
(Converse wiring of S1 and S2, or
break of S3 wiring.)
(2)When LED3 is blinking.
Indoor/outdoor connecting wire is nor-
mal.
Check LED display on outdoor controller
circuit board. Refer to 10-10.
Check protection device connector (63L
and 63H) for contact failure.
Refer to 10-9.
Normal operation
Judgment and action
Countermeasure