Procedure 2: Replacing P.c. Board - Toshiba MMY-MAP0804HT8-E Service Manual

Procedure 2: Replacing P.C. Board

1
Replace the faulty P.C. board with a service P.C. board.
Be sure to replicate the old jumper setting (removal), switch setting (SW501), and connector short-circuit
setting (e.g. CN34) on the service P.C. board. (See the diagram at below.)
2
It is necessary to establish a one-to-one correspondence between the indoor unit being serviced
and the remote controller.
Turn on the indoor unit using one of the methods described below according to the system configuration.
(1) Single (stand-alone) operation
Turn on the indoor unit and proceed to Procedure 3.
(2) Group operation
A) If it is possible to selectively turn on the indoor unit being serviced
Turn on the indoor unit being serviced and proceed to Procedure 3.
B) If it is not possible to selectively turn on the indoor unit being serviced (Case 1)
a) Temporarily disconnect the group control wiring from terminals A and B of the indoor unit being serviced.
b) Connect the remote controller wiring to the terminals, turn on the indoor unit, and proceed to Procedure 3.
* If this method cannot be used, proceed to the alternative method described below (Case 2).
C) If it is not possible to selectively turn on the indoor unit being serviced (Case 2)
a) Remove the CN41 connectors of all other indoor units in the same group.
b) Turn on the indoor unit and proceed to Procedure 3.
Case 1
Case 2
Remove CN41
connectors of all
other indoor units
in same group.
* Be sure to restore the temporarily removed group control wiring and CN41 connectors to their initial states after
Procedure 3 has been completed.
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Connector for drain pump (CN504)
(MCC-1570)
CN34
SW501
(red)
J01
If a short-circuiting plug had been used on the
replaced P.C. board, reuse it on the service P.C. board.
(MCC-1402)
CN34
From left: CN112, 111 and 110
If a short-circuiting plug had been used on the
replaced P.C. board, reuse it on the service P.C. board.
Indoor unit Indoor unit
P.C. board
A B
Group control wiring
Indoor unit Indoor unit
P.C. board
CN
41
A B
Group control wiring
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The type and capacity of the indoor unit
are necessary for fan speed setting.
* Set the jumper wire J02 according to
the capacity class as shown below.
J02
J02
AP009~AP030 Cut
AP036~AP056 Present (factory default)
Be sure to set this jumper as required to make
the selection of a motor protection level possible.
CN41 (MCC-1403)
If a short-circuiting plug had been used on the replaced
P.C. board, reuse it on the service P.C. board.
Indoor unit (one being serviced)
P.C. board Service P.C. board
A B A B
Remote controller
Indoor unit (one being serviced)
P.C. board Service P.C. board
A B A B
Remote controller
279
CN041
CN030
Remove group control wiring from terminals
A and B of indoor unit being serviced, and
connect remote controller wiring.