Mitsubishi Electric PUZ-ZM60VHA2, Service Manual

Page: 52 / 140

52
OCH771
10-4. TROUBLESHOOTING OF PROBLEMS
Check Code Abnormal points and detection method Cause Judgment and action
A8
(6608)
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 control-
ler that did not reply (ACK).
1
Transmitting condition is repeated
fault because of noise and the
like.
2
Voltage drop and weak signal
which lead communication error
are caused by over-range trans-
mission wire.
• Maximum distance ...... 200 m
• Remote controller line (12 m)
3
Voltage drop and weak signal
which lead communication error
are caused by type-unmatched
transmission wire.
Type.........
With shield wire-
CVVS, CPEVS
With normal wire (no shield)-
VCTF, VCTFK, CVV
CVS, VVR, VVF, VCT
Diameter ..... 1.25 mm 2 or more
4
Accidental malfunction of abnor-
mality-generated controller
1
Check transmission waveform or noise on
transmission wire.
2
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
malfunction was accidental, the unit returns
to normal. If the same abnormality occurs
again, controller of displayed address and
attribute may be defective.
Phenomena Factor Countermeasure
1. Remote controller display does not
work.
1
12 V DC is not supplied to remote controller.
2
12–15 V DC is supplied to remote controller, however,
no display is indicated.
• “Please Wait” is not displayed.
• “Please Wait” is displayed.
1
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 phenomena No.3 below.
2
Check the following.
• Failure of remote controller if “Please
Wait” is not displayed
• Refer to phenomena No.2 below if
“Please Wait” is displayed.
2. “Please Wait” display is remained on
the remote controller.
1
At longest 2 minutes after the power supply “Please
Wait” is displayed to start up.
2
Communication error between the remote controller
and indoor unit
3
Communication error between the indoor and outdoor
unit
4
Outdoor unit protection device connector is open.
1
Normal operation
2
Self-diagnosis of remote controller
3
“Please Wait” is displayed for 6 minutes
at most in the 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.
(Reversed wiring of S1 and S2, or
break of S3 wiring.)
(2) When LED3 is blinking,
indoor/outdoor connecting wire is
normal.
4
Check LED display on outdoor controller
circuit board. Refer to "10-9. FUNCTION
OF SWITCHES, CONNECTORS AND
JUMPERS".
Check protection device connector (63H)
for contact failure.
Refer to "10-8. TEST POINT DIAGRAM".
3. When pressing the remote controller
operation switch, the OPERATION
display is appeared but it will be
turned off soon.
After cancelling to select function from the remote
controller, the remote controller operation switch will
not be accepted for approx. 30 seconds.
Normal operation