Board Replacing Procedures - Toshiba MMD-AP0481HF2UL Service Manual

14. P. C. BOARD EXCHANGE PROCEDURES
Indoor unit
14-1. Replacement of indoor P.C. board
Part code Model type P.C. board type
∗∗∗
431-6V-588 MMD-AP HF2UL series MCC-1403
< Set the type code and capacity code and then set DN [C8] = [ 0001 ] >
Points to note when replacing indoor P.C. board assembly
The electrically erasable programmable read-only memory (hereinafter EEPROM, IC010) mounted on an
indoor P.C. board holds important setting data, including the type and capacity codes intrinsic to the model (set
at the factory), as well as the line / indoor / group addresses, high ceiling adjustment setting and the like
(during installation, either automatically or manually). Proceed with the replacement of an indoor P.C. board
assembly in accordance with the procedure described below.
After completion of the work, check the settings again, including the indoor unit No. and group header / follower
designation, and confirm the integrity of the refrigerating cycle by conducting a test operation, etc.
<Replacement procedure>
Method 1
If it is possible to turn on the indoor unit and read the setting data from the P.C. board to be replaced via a
wired remote control -
Reading EEPROM data: Procedure 1
Replacing P.C. board and turning on power: Procedure 2
Writing EEPROM data in new EEPROM: Procedure 3
Resetting power supply (applicable to all indoor units connected to remote control in case of group operation)
Method 2
If it is not possible to read the setting data due to the failure of the EEPROM itself -
Replacing P.C. board and turning on power: Procedure 2
Writing EEPROM data on basis of information supplied by customer (e.g. high ceiling adjustment setting and
optional connection setting): Procedure 3
Resetting power supply (applicable to all indoor units connected to remote control in case of group operation)
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