Daikin GYEQ20AN Service Manual page 138

Troubleshooting the Outdoor Unit
[After replacing the mixer, regulator, or engine]
If you have replaced the mixer, regulator, or engine, clear the initial GVM correction amount.
• These clearing operations must be performed after replacing the part. For information on the
NOTE: Be sure to clear the correction amount after replacing these parts. Failing to do so may
Replacing the main circuit board requires the update of the main CPU software and the
reinstallation of the EEPROM on the new main circuit board.
Fig. 4.8/Location of the software update switch and the EEPROM on the main circuit board
1. Before following the replacement procedure, write down the total operating time shown on
2. Turn OFF the outdoor unit's main power supply breaker. Make sure that none of the LEDs
3. Remote the main circuit board and then remove the EEPROM from the main circuit board.
4. Reinstall the removed EEPROM onto a new main circuit board.
5. Install the new main circuit board into the outdoor unit.
6. Write the main CPU software onto the new main circuit board.
7. Write the version of the written software into the software version entry area of the new main
8. Perform sufficient actuator checks and test runs to ensure that operation is normal.
127
operating methods, see page 114 [How to Use the Checker on PCB] and page 121 [STOP Mode].
cause the engine to stall.
Replacing the main circuit board
the 7-segment hour meter.
on the circuit board are lit. It is dangerous if there are residual electrical charges.
(The main CPU software is not prewritten onto the spare circuit board.)
(1) Connect a PC to the main circuit board. (In the same way as for the PC checker.)
(2) Write the main CPU software.
• Set SW12 on the main circuit board to the "Main CPU writing" side.
• Turn ON the outdoor unit's main power supply breaker and make sure that "P on" is
shown on the 7-segment display.
• Using the writing application installed on the PC, write the main CPU software.
• When finished writing the main CPU software, exit the writing application and turn OFF
the outdoor unit's main power supply breaker.
• Turn SW12 on the main circuit board back to the "Normal" side.
(3) Make sure that the main CPU software is written and runs successfully. Check also that
the version of the written software is correct.
• Turn ON the outdoor unit's main power supply breaker and make sure that "P on" is
shown temporarily on the 7-segment display.
• Check that LED5 on the main circuit board is flashing.
• Make sure that the total operating time on the 7-segment display shows the time you
wrote down at the beginning of this replacement procedure.
• Using the onboard checker, press
• Make sure that no parts on the circuit board are damaged and that all the connectors
are correctly inserted.
circuit board.
and check the version of the main CPU software.
UP
SiAUY361411EA
Troubleshooting