Daikin VRVII Manual page 268

Troubleshooting by Indication on the Remote Controller
Disconnect the cable from
the fan, and then check
Power OFF the fan motor for the
insulation resistance.
Check the inverter power
transistor.
A
The
insulation
resistance is low (i.e.,
not more than
1MΩ.)
NO
Has the
power transistor got
defective?
NO
B
YES
Replace the fan
motor.
Replace the fan
driver.
YES
Replace the
inverter PCB.
Observe the
conditions of
the PCB.
In the case of a
serious failure,
a compressor
failure may
cause the
failure of the
PCB. Even if
the PCB is
replaced, it
may cause
failure again.
To avoid that,
recheck the
compressor for
ground and for
any broken
wires.
Furthermore,
even after the
completion of
PCB
replacement,
check the
compressor.
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