How To Replace The Pc Board For Service On The Air To Air Heat Exchanger - Toshiba VN-M150HE Service Manual

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How to replace the PC board for service on the
Air to Air Heat Exchanger
<Model>
VN-M**HE series
Note for replacing the PC board for service on the Air to Air Heat
Exchanger
Before replacing the PC board on the Air to Air Heat Exchanger, non-volatile memory (hereinafter referred to as EEPROM (IC503)) on
it stores the important data such as the model code, the capacity code (factory default), the group address, and the 24-hour ventilation
settings set automatically or manually (when installing the unit). Follow the procedure below to replace the PC board for service on the
Air to Air Heat Exchanger. After replacing the board, confirm the settings of the Air to Air Heat Exchanger unit No. and the header/
follower configuration in the group. In addition, perform a test run.
Replacement procedure
▼ Case 1
When you can turn on the Air to Air Heat Exchanger and can
read the setting data from the wired remote controller before
you replace the board
Readout of EEPROM data. *1 (See page 140.)
Replace the PC board for service and turn the power on. *2 (See
page 140.)
Writing-in of the readout EEPROM data. *3 (See page 141.)
Reset the power supply (for all Air to Air Heat Exchangers
(including the indoor units) connected to the remote controller
while performing group operation).
▼ Case 2
When you can neither turn on the Air to Air Heat Exchanger
nor operate the wired remote controller due to a problem
with the feeder circuit (when there is a problem with the
circuit board) before you replace the board
Replace the EEPROM (IC503). (For details, see "EEPROM
arrangement figure" on page 141.)
Readout of EEPROM on the PC board, then attach the EEPROM
for service.
Replace the PC board for service and turn the power on. *2 (See
page 140.)
Readout of EEPROM data. *1 (See page 140.)
If the data cannot be read, go to Case 3.
Replace the EEPROM (IC503). (For details, see "EEPROM
arrangement figure" on page 141.)
Reattach the EEPROM for service. (Attach the EEPROM as
before on the PC board for service.)
Replace the PC board for service and turn the power on. *2 (See
page 140.)
Writing-in of the readout EEPROM data. *3 (See page 141.)
Reset the power supply (for all Air to Air Heat Exchangers
(including the indoor units) connected to the remote controller
while performing group operation).
▼ Case 3
When you cannot read the setting data due to a problem with
the EEPROM before you replace the board
Replace the PC board for service and turn the power on. *2 (See
page 140.)
Writing-in of the setup the setting data such as the model code,
capacity code, 24-hour ventilation settings etc. on the EEPROM
according to client information. *3 (See page 141.)
Reset the power supply (for all Air to Air Heat Exchangers
(including the indoor units) connected to the remote controller
while performing group operation).
139
411-75-190
(MCC-1615)