28
B
B
Check of serial signal
Turn on power supply.
No
Yes
Yes
No
No
Yes
No
Yes
Start
Check the connecting of main circuit parts and connectors (CN501: I.P.M P. C. board,
CN 801: Electronic control P. C. board, CN554: relay P. C. board).
Is there voltage of 230V AC in the
power supply terminal block?
Is there voltage of 310V DC - 340V DC
across the smoothing capacity?
Is there voltage of 230V AC across
the output cables (LD63, LD64) in the
noise filter P. C. board?
Check the power supply cable.
Check the main circuit parts
and replace it.
Replace the electronic control P. C. board.
Replace the noise
filter P. C. board.
Is there voltage of 230V AC across
the input terminal part in the diode
module (DS61)?
Replace the current
limiting resistor.
w
When replacing, check the
connection of connector
CN720 in the outdoor
electronic control P. C.
board.
A
A
Check of power supply
No
Yes
Start
1. Check the indoor unit with referring to the indoor unit service manual.
2. Turn off the power supply of the indoor and outdoor unit and return the indoor/ outdoor unit
connecting wire to former original.
3. Check the connection of indoor/ outdoor unit connecting wire in the outdoor unit terminal block,
and check the connection of the connectors (CN601: unit A, CN 602: unit B, CN603: unit C,) in
the electronic control P. C. board.
4. Disconnect the lead wire to the compressor. Turn on the power supply (indoor/ outdoor unit)
3 minutes later, EMERGENCY OPERATION starts.
Is there voltage of 5V DC - 10V DC between
No. 3 (+) and N (-) in the outdoor terminal block?
Replace the electronic control P. C. board.
Recheck a connected circumstance of the indoor/ outdoor unit connecting wire.
Outdoor unit does not operate. (LED display: display OFF)
Outdoor unit does not operate. (LED display:
0
00
0
)
OB287B--1.qxp 06.6.7 11:13 AM Page 28
Summary of Contents for MXZ-24UV
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