Toshiba MMD-AP0076BHP-E Service Manual page 88

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.)
CAUTION
Don't remove the materials.
No materials. The power I.C. (IC101) may break.
< The front of the P. C. Board>
CN73
J01
(RED)
T01
IC503
2 1
SW501
IC101
Perform the same setting of the jumper wire(J01) setting(cut),
switch(SW501) as the setting of the P. C. board before replacement
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
Indoorunit
Case 2
Indoorunit
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.
< The Back of the P. C. Board>
C08
C09
Indoorunit (one being serviced)
Indoorunit
P.C. board P.C. board
A B A B
Group contrpl wiring
Indoorunit (one being serviced)
Indoorunit
P.C. board P.C. board
CN
41
A B A B
Group contrpl wiring
Materials
Service P.C. board
A B
Remote
controller
Service P.C. board
A B
Remote
controller
– 88 –
Remove group control wiring
from terminals A and B of
indoor unit being serviced,
and connect remote controller
wiring.